KABUL, Afghanistan  Afghanistan’s defense minister confirmed Sunday that a police captain was connected with the group behind the assassination attempt on President Hamid Karzai a week earlier and that an army officer supplied the weapons and ammunition used in the attack.

Both men have been arrested and are under investigation for their suspected role in the attack on the military parade, which killed three people, including a member of Parliament, and wounded 11. One of the suspects may have been a sympathizer, and the other was probably motivated by money, Defense Minister Abdul Rahim Wardak said.

Afghanistan’s intelligence chief, Amrullah Saleh, blamed Al Qaeda for the attack. He said three of the men involved were in contact with people outside Afghanistan, including people in Miram Shah, a town in Pakistan’s tribal region of North Waziristan, the main base for Taliban and Al Qaeda in the region.

The three, who were killed in a house raid Wednesday, include an Afghan named Homayoun, suspected of directing an attack on the Serena Hotel in Kabul in January, and two foreigners who were planning suicide bombings in the city.