Afghan President Hamid Karzai at the peace conference June 2. (Musadeq Sadeq/Associated Press)

Two senior Afghan officials left the government Sunday after a serious security breach during a peace conference involving tribal leaders on June 2.

The head of the National Directorate of Security, Amrullah Saleh, and Interior Minister Hanif Atmar either resigned or were fired, reports said.

They were in charge when the Taliban fired rockets at the gathering and then suicide attackers moved against the conference in Kabul, where 1,600 dignitaries assembled to discuss peace in the war-torn country.

No delegates were hurt but two attackers were killed and one captured. The failure of the attack raised questions about why the two officials had to go.

A statement from President Hamid Karzai's office said the men had failed to give satisfactory explanations for their actions.

"The president of Afghanistan has lost trust in our capability to protect national events," Saleh said.

The two top officials were seen as allies of the U.S.

"Both the ministers of interior and intelligence are people we admire and whose service we appreciate," said Pentagon spokesman Geoff Morrell.

The departure of the two men is expected to disrupt the government. They left on the same day that Karzai ordered a review of all Taliban suspects held by the government, and said those held on weak evidence would be released.

"There will be a massive fallout from these resignations both in the Interior Ministry and the NDS as alliances are shuffled," said Candace Rondeaux, who monitors Afghanistan for the Brussels-based International Crisis Group think tank.

"They appear to be forced resignations, and reflect significant worries of Karzai's administration over the loyalty of those leading key security agencies in the country," she said.

With files from The Associated Press