KABUL, Afghanistan -- A team of suicide bombers attacked a compound belonging to Afghanistan's spy agency Wednesday, killing at least one guard and injuring 33 civilians in a brazen strike at the heavily fortified heart of Kabul, the capital, officials said.
One of the attackers detonated a minivan packed with explosives at the entrance to the National Directorate of Security, said agency spokesman Shafiqullah Tahiri.
Five others in suicide vests drove up in a separate van and were killed in an exchange of fire with security forces, he told a news conference. Their vehicle was also rigged to explode. Security forces deactivated the device with three minutes left on the timer, Mr. Tahiri said.
The Taliban claimed responsibility for the midday attack.
"The attack took place when some advisers of the occupying countries had just arrived at the National Directorate of Security compound in order to participate in a very important meeting," the militants said in a statement. "Our initial information says that as a result of this successful attack, many intelligence officers and many intelligence employees and many foreign advisers were killed and wounded."
A NATO spokesman said its forces were not involved in the attack.
The militants' show of violence happened days after President Barack Obama announced that international forces are accelerating the handover of lead responsibility for securing Afghanistan to the national security forces. The departure of most foreign troops next year has many in Kabul worried about a deterioration in security.
But Afghan President Hamid Karzai praised the "dedication and bravery" of the security forces, whose quick response Wednesday, he said in a statement, prevented a second explosion that could have caused more casualties.
Sediq Sediqqi, spokesman for the Interior Ministry, which oversees the police, said: "Six suicide bombers were killed within less than 10 minutes, which is itself an assurance to the people of Afghanistan."
It was the second time the National Directorate of Security was targeted in less than two months. In December, agency director Asadullah Khalid was injured in a suicide bombing at a directorate guest house in Kabul. He is receiving treatment in the United States.
Wednesday's attack happened in a heavily trafficked area that also houses the police headquarters, Interior Ministry and several foreign embassies. The blast, which could be heard across central Kabul, left a trail of charred cars, shattered glass and other debris.