Afghan officials say the government employees who were arrested were low-ranking workers in the Defense and Interior ministries. Karzai escaped unharmed, but three others were killed in the attack.
Defense Minister Abdul Rahim Wardak identified one of the arrested government workers as a man named Jawed from Kapisa Province, north of Kabul. Wardak says Jawed repaired weapons at an Afghan Defense Ministry factory. He alleges Jawed provided two AK-47 assault rifles and a machine gun to three gunmen who attacked Karzai during a Kabul military parade on April 27.
Wardak identified the second suspect as a police nurse named Zalmay from the Jabal Saraj district of Parwan Province, also north of Kabul. Wardak says Zalmay had been in contact with one of the key organizers of the failed assassination plot.
Although authorities in Kabul have not released details about who they think organized the plot, Afghan intelligence chief Amrullah Saleh insists the masterminds behind the attack on Karzai were Al-Qaeda-linked militants based in neighboring Pakistan. Saleh says Kabul has provided information on the militants' whereabouts to "relevant international sources" who have the capacity to "put pressure on those people who are outside our borders."
"Pakistan has agreed with them and told them that jihad is fair against the people of Afghanistan," Saleh says. "This should once again make our people united and see how deep the roots of this crisis go."
Escaped To Pakistan
Saleh says a raid on April 30 by Afghan security forces on a Taliban hideout in Kabul killed a militant involved in planning a suicide-bomb attack on Kabul's Serena Hotel in January that killed eight people. Saleh says that militant, known as Humayun, had escaped to Pakistan after the Serena Hotel bombing but returned to support last week's attack on Karzai.
Intelligence officials have said previously that Humayun had links to a network headed by militant leader Siraj Haqqani. That network is associated with the Taliban and also is thought to have links to Al-Qaeda fighters. It is part of a myriad of militant groups that support Afghanistan's former hard-line Islamist regime and that are trying to topple Karzai's Western-backed government.
Saleh charges that the recent violence in Kabul shows that authorities in Pakistan's tribal regions continue to allow Al-Qaeda-linked militants to cross into Afghanistan to commit terrorist attacks.
"In what the Pakistanis are doing, we see two faces," Saleh says. "On one hand, we see a fight against terrorism. But on the other hand, they are agreeing with terrorist groups -- telling them to stay out of Pakistani cities but turning a blind eye if they go to Afghanistan."
Pakistan has repeatedly denied such allegations from Kabul in the past, noting that Pakistani security forces have arrested Taliban and Al-Qaeda-linked suspects on its soil. The United States has launched missile strikes on suspected Al-Qaeda hideouts in Pakistan, even though Islamabad condemns those attacks as a breach of its sovereignty.
Domestic Political Rivals
Last week's attack on Karzai led to speculation and allegations in Afghanistan's lower chamber of parliament, the Wolesi Jirga, that Karzai's domestic political rivals may have been involved.
Legislator Shukria Barakzai tells RFE/RL that she does not think the arrests of the two Afghan government workers will be the final result of the investigation by a specially appointed Afghan commission. Barakzai says such an assassination attempt is a "major plot" that could not have been planned by just one or two people.
"I think Afghanistan's current administration has two kinds of enemies," Barakzai says. "One kind goes by the name 'Taliban' and clearly says that it is the enemy. The second is inside the system itself, representing old political parties with old aims. They are destroying the system from the inside. If this appointed commission doesn't find anything else besides these two low-ranking government employees, nobody in Afghanistan will trust such commissions in the future."
Last week, Afghan lawmakers passed a vote of no confidence against Wardak, Saleh, and the interior minister after they revealed they had been aware of a plot against Karzai but failed to stop it. Despite the no-confidence vote, all three security officials retained their jobs.
RFE/RL Radio Free Afghanistan correspondents Zakfar Ahmadi in Kabul and Ibrahim Amiri in Prague contributed to this report