Authorities have arrested two Afghan government employees for alleged involvement in last week's plot to kill President Hamid Karzai, top officials said.
But the government maintained that al-Qaida-linked militants based in neighboring Pakistan masterminded the April 27 attack on a military parade in Kabul. Karzai escaped unharmed but three others were killed.
"Al-Qaida was involved in the attack. That is very clear from us," intelligence chief Amrullah Saleh told a news conference Sunday.
Defense Minister Abdul Rahim Wardak identified one of the arrested government employees by a single name, Jawed, and said he had worked at a Defense Ministry factory repairing weapons. He allegedly provided two AK47 assault rifles and a machine-gun to the three gunmen.
Pakistan has sometimes nabbed Taliban and al-Qaida suspects on its soil. The US has also launched missile strikes on suspected al-Qaida hideouts inside Pakistan, although Islamabad condemns it as a breach of its sovereignty.