KABUL, Afghanistan (AP) — Suicide attackers blew up a car bomb and battled security forces outside Afghanistan’s presidential palaceTuesday after infiltrating one of the most secure areas of the capital. The army said the attackers were killed but knew of no other deaths.

The Taliban claimed responsibility for the attack, which came as reporters were gathering for a news event on Afghan youth at whichPresident Hamid Karzai was expected to talk about ongoing efforts to open peace talks with the militant group.

The palace is in a large fortified area of downtown Kabul that also includes the U.S. Embassy and the headquarters for the NATO-led coalition forces. Access is heavily restricted. It houses Karzai’s residence but it was not immediately clear whether the president was in the building at the time and his spokesman did not answer his phone.

Gunfire started around 6:30 a.m. inside a heavily guarded area near the east gate leading to the palace next to the Afghan Ministry of Defense and the former Ariana Hotel, which former U.S. intelligence officials have confirmed is used by the CIA.

Kabul police chief Gen. Mohamad Ayub Salangi said three or four gunmen jumped out of their SUV and opened fire after being stopped by security forces while trying to use fake documents to get through a checkpoint. All gunmen were killed, and one palace security guard was wounded, he said.

A car bomb then exploded as it tried to enter the area. About 20 journalists took cover behind a religious shrine, pulling a schoolboy off the street who had been caught in the open on his way to school.

Taliban spokesman Zabihullah Mujahid claimed responsibility, saying in a text message the militants had “brought death to the enemy” with a suicide attack. He later suggested in an emailed statement that all three buildings had been targeted, saying the attack came “near the Ariana Hotel, the important CIA base, and also the presidential palace and Ministry of Defense.”

Smoke could be seen coming from the area of the hotel, but there was no immediate indication any of the buildings were hit in the attack.

Mujahid claimed the attackers had inflicted “heavy casualties,” but Afghanistan’s Kabul division army commander Gen. Kadam Shah Shahim said he knew of no deaths among security forces or civilians.

He said his forces killed all of the attackers after they jumped out of their vehicle and opened fire.

The NATO-led coalition in Afghanistan instituted a camp lockdown during the incident and said in a short statement that its forces had been ready to assist but were not called in by Afghan authorities.

The U.S. Embassy cancelled all consular appointments and advised American citizens in Kabul to stay indoors but had no immediate comment on the incident.

The Taliban have indicated they are willing to open peace talks with the U.S. and the Afghanistan government and just last week opened an office in Qatar for possible negotiations.

But at the same time they have not renounced violence and attacks have continued across Afghanistan.

 Afghanistan: The Taliban claimed responsibility Wednesday for an attack in Afghanistan that killed four American troops just hours after the insurgent group announced it would hold talks with the U.S. on finding a political solution to ending the nearly 12-year war in the country.

The deadly attack underscores the challenges ahead in trying to end the violence roiling Afghanistan through peace negotiations in Qatar with militants still fighting on the ground.

Taliban spokesman Zabiullah Mujahid said the insurgents fired two rockets into the Bagram Air Base outside the Afghan capital, Kabul, late on Tuesday. American officials confirmed the base had come under attack by indirect fire — likely a mortar or rocket — and that four U.S. troops were killed.

Also Tuesday, five Afghan police officers were killed at a security outpost in Helmand province by apparent Taliban infiltrators — the latest in a string of so-called “insider attacks” that have shaken the confidence of the nascent Afghan security forces.

The attacks came as the Taliban opened a political office in the Qatari capital of Doha, and announced they were ready for peace talks. The decision was a reversal of months of failed efforts to start negotiations while Taliban militants intensified a campaign targeting urban centers and government installations across Afghanistan.

President Barack Obama cautioned that the peace talks with the Taliban would be neither quick nor easy but that their opening a political office in Doha was an “important first step toward reconciliation” between the Islamic militants and the government of Afghanistan.

In setting up the office, the Taliban said they were willing to use all legal means to end what they called the occupation of Afghanistan — but did not say they would immediately stop fighting.

American officials said the U.S. and Taliban representatives will hold bilateral meetings in the coming days. Afghan President Hamid Karzai’s High Peace Council is expected to follow up with its own talks with the Taliban a few days later.

The Taliban announcement followed a milestone handover in Afghanistan earlier Tuesday as Afghan forces formally took the lead from the U.S.-led NATO coalition for security nationwide. It marked a turning point for American and NATO military forces, which will now move entirely into a supporting role.

Kabul deputy police chief Mohammad Daoud Amin said the blast was in the Pul-e-Surkh area of the western part of the city, which is miles (kilometers) away from the site of the handover ceremony attended by NATO chief Anders Fogh Rasmussen and Afghan President Hamid Karzai.

A police officer named Asadullah said the target was the convoy of Mohammed Mohaqiq, a prominent ethnic Hazara lawmaker who is a former Cabinet member. Asadullah, who like many Afghans uses just one name, said he saw two dead bodies lying in the street and a police vehicle was destroyed in the blast.

Mohaqiq survived the blast, according to Nahim Lalai Hamidzai, another member of the Afghan parliament.

Gen. Mohammad Zahir, chief of the Kabul Criminal Investigation Division, said three people were killed by the bombing and another 30 were wounded — including six bodyguards.

“The roadside bomb targeted the Mohaqiq convoy, but he safely passed. One of his vehicles was damaged,” Zahir said.

The leader of the People’s Islamic Unity Party of Afghanistan, Mohaqiq is a member of the National Front, which represents members of the former Northern Alliance that fought the Taliban before the U.S. invasion in 2001. The predominantly ethnic Pashtun Taliban persecuted the Hazara minority during their five-year rule that imposed a radical interpretation of Islamic law.

District chief Nayamatullah Samim said that the policemen’s bodies were discovered in the shelter near their checkpoint Wednesday night, after they did not check in with their superiors. Two other officers assigned to the checkpoint were missing, along with vehicles and weapons.

“We don’t know yet whether these two missing men are the ones who killed the police or if they were taken by other attacks,” Samim said.

So-called “insider attacks” in which Afghan forces open fire on their comrades or international forces threaten to shake the confidence of the two sides as the 2014 withdrawal of most of the international troops approaches.

Taliban insurgents have warned they would infiltrate Afghan security forces to carry out insider attacks. There have been several such attacks in the past year, including officers poisoned while eating.

The most recent such attack was May 28, when two recently rehired Afghan police opened fire on their commander at a checkpoint in a remote district in the country’s south, killing him and six of his men before fleeing in a police vehicle with weapons.

On May 5, an Afghan soldier turned his weapon on two U.S. Marines he was working with and killed them.

The insurgents have stepped up attacks across the board in recent weeks, bringing violence to among the highest levels of the 12-year war as they seek to weaken the government and security forces. Foreign troops have been pulling back from front-line fighting in preparation for the international coalition turning over full responsibility for security to Afghan units later this year.

Baghlan provincial council leader Mohammad Rasoul Mohseni was entering the compound in the morning when the bomber ran up on foot and detonated his explosives, police spokesman in Baghlan province Jawed Bashrat said.

Provincial chief of police Asadullah Sherzad said 14 people were killed, including Mohseni, and 11 were wounded.

Mohammad Zahier Ghanizada, a member of parliament from Baghlan, confirmed the council chief’s death and added that Mohseni had previously received multiple death threats.

Also killed in the attack were six police bodyguards and seven civilians, Sherzad said.

Taliban spokesman Zabiullah Mujahid claimed in a text message to journalists that an insurgent operative carried out the targeted bombing.

“Today at 11 a.m. in front of the Baghlan provincial council office, we have carried out a suicide attack and killed the head of the council,” it said.

Seeking to weaken the Afghan government, the main Taliban insurgents have been carrying out attacks and assassinations intended to intimidate both officials and civilians ahead of next year’s withdrawal of most international troops.

Afghan President Hamid Karzai condemned the bombing Monday.

“Such attacks are against all human rights and the principles of Islam,” Karzai said in a statement. “Perpetrators of such attacks are enemies of the Afghan nation and the puppets of foreigners.”

Karzai left later Monday for a two-day state visit to India, where he is expected to request military aid.

Both Karzai and the U.S. have sought peace talks with the Taliban and other insurgent factions in preparation for most foreign troops leaving next year after more than 12 years of war, but the efforts have borne little fruit. The Taliban seek to re-establish the strict interpretation of Islamic law they imposed for five years before being ousted in the 2001 U.S.-led invasion over its sheltering of al-Qaida’s terrorist leadership.

The insurgents last month launched a fierce new spring offensive that has in the past week alone seen the police chief of Farah province gunned down outside his home and twin bombings that killed nine people in an elite gated community for government officials and business owners outside of the southern city of Kandahar. Two bombs also exploded outside the provincial governor’s office in Nangarhar province last week, killing one police guard.

Insurgents have also targeted members of the international coalition. A roadside bomb killed four American soldiers last week in the country’s south, while another insurgent faction, Hizb-e-Islami, targeted a coalition convoy in the capital of Kabul two days later, killing two U.S. soldiers and four American contractors who were training Afghan troops to take over security.

Kandahar province’s police chief Gen. Abdul Raziq said the Monday blast wounded another 12 people in Maroof district, roughly 60 kilometers (36 miles) northeast of Kandahar city.

Insurgents plant landmines and roadside bombs in the south and the east of the country to target Afghan and international troops, but civilians often are killed or injured as a result.

Defense Ministry spokesman Mohammad Zahir Azimi said on Wednesday that Afghan troops will fill the “vacuum” caused by the withdrawal of 34,000 U.S. troops over the next 12 months.

Obama told Americans about his decision in his State of the Union speech. He had earlier briefedAfghan President Hamid Karzai.

Karzai’s office said the two leaders discussed strengthening and equipping the Afghan forces and a pending security agreement that will determine whether the U.S. will retain soldiers here after most foreign troops leave at the end of 2014.