KABUL, Afghanistan - Gunmen in Afghan police uniforms opened fire on NATO troops on Monday in southern Afghanistan, killing two Albanian soldiers and wounding another international service member, officials said.

The attack by suspected Afghan policemen appears to be the latest in a growing number of turncoat attacks that have raised questions about the vetting of Afghan recruits and threatened the international military commitment to Afghanistan.

Last month, France suspended its training program and threatened to withdraw its forces a year ahead of schedule after an Afghan soldier shot and killed four French soldiers on a base in eastern Afghanistan.

Monday's shooting occurred in the village of Robat, in Kandahar province's Spin Boldak district which borders Pakistan, said Kandahar police chief Abdul Raziq. The troops had gone there for a meeting about opening two schools and a health centre, the Albanian defence ministry said.

The soldiers "found themselves attacked by a group of persons wearing uniforms of the Afghan police," Brig. Gen. Viktor Berdo, the head of Albanian land forces, told reporters in the country's capital Tirana.

The attackers opened fire with five assault rifles and one light automatic machine-gun, the Albanian Defence Ministry said. The two Albanians, a captain and a corporal, died later in a hospital in the provincial capital of Kandahar city. Another international soldier was wounded, the ministry said, without providing a nationality.

Albanian President Bamir Topi denounced the attack as a "grave terrorist act" and called for the punishment of those responsible.

It was the first time any of Albania's soldiers have been killed in Afghanistan. The country has 265 troops in the country.

Eleven Afghan policemen were arrested after the shooting, the ministry said.

There have been more than 45 of these insider attacks in Afghanistan since 2007, more than 75 per cent of those in the last two years, according to Pentagon data.

Monday's attack on NATO forces came after a suicide car bomber struck a police station in the provincial capital of Kandahar city.

The attacker drove a Toyota Corolla up to the checkpoint outside of the Kandahar police station and detonated his explosives, Raziq said. One police officer was killed and four people were wounded in the explosion -- two police officers and two civilians, he added.

A civilian compound nearby was also destroyed, according to a statement from the Kandahar government's media office.

No one immediately claimed responsibility for the attack, but it fit the pattern of Taliban assaults, which usually focus on government installations or security forces.

Also Monday, three Italian soldiers were killed in a vehicle accident in the west of the country.

Italian President Giorgio Napolitano issued a condolence message expressing his "deep emotion" over the news of the deaths in Herat province.

The Italian soldiers were in a convoy going to survey a canal project in Herat's Shindand district when their vehicle crashed into a canal, said provincial police spokesman Rauf Ahmadi. The Italian news agency ANSA said that the soldiers' armoured vehicle overturned while crossing a stream.