At least three suicide bombers attacked a police training centre Monday in the southern Afghan city of Kandahar, killing one American — a civilian contractor, officials said.

NATO soldiers and policemen examine the damage caused after at least three suicide bombers attacked a police training centre in Kandahar on Monday. (Allauddin Khan/Associated Press)

One of the attackers drove an explosives-laden car up to the gate of the centre and detonated the bomb, blowing a hole in the compound wall, the Interior Ministry said.

Two other bombers tried to storm through the hole, engaging in a gunfight with police before blowing themselves up outside.

Gen. Gul Nabi Ahmadzai, head of police training programs for Afghanistan, gave a slightly different account, saying the two gunmen were killed in firing by police.

Taliban spokesman Qari Yousef Ahmadi claimed responsibility for the attack and said four bombers were sent. The different accounts could not be immediately reconciled.

No police were wounded in the brazen midday attack, which could be heard throughout the city of Kandahar. NATO and Afghan forces swarmed the training centre, but it appeared to be secure about an hour after the explosion.

The Taliban have struck the city recently with a slew of bombings and assassinations of people seen as government allies.

Karzai removes 2 top officials

Monday's attack came the day after Afghan President Hamid Karzai removed two of the country's top security officials — each with longtime ties to American forces — over an attack on a national conference exploring peace with the Taliban.

The removals Sunday of the interior minister and intelligence chief surprised U.S. officials and may cause major disruption within Afghanistan's intelligence and security establishment at a critical juncture while the U.S. and NATO escalate the war and the Afghan government commits to offering peace to the insurgents.

The move is likely to fuel speculation over differences within the Karzai administration over its efforts to reconcile with the Taliban, including the possible release of hundreds of detained militant suspects.

The head of the National Directorate of Security, Amrullah Saleh, was a senior figure in the Northern Alliance that helped the U.S. oust the Taliban regime in 2001. As a young man, Interior Minister Hanif Atmar served in Afghanistan's Communist-era intelligence agency and fought mujahedeen opposed to the Soviet occupation.

"It's a very significant event. There will be a massive fallout from these resignations both in the Interior Ministry and the NDS as alliances are shuffled," said Candace Rondeaux, senior analyst on Afghanistan for the 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.

Sunday's resignations were a surprise, particularly since the attack on the jirga conference in Kabul last week was thwarted. Security officials have rarely faced punishment or resigned over previous major attacks in the capital.

Karzai left Afghanistan on Monday to attend an international conference in Spain, cancelling a news conference he had scheduled earlier. His spokesman, Waheed Omer, insisted the security lapse at the peace conference was the only reason for the two resignations.

"This could have been national chaos, a national crisis" if the attack had succeeded, Omer told reporters. "Somebody had to take responsibility for this."