Kabul  - An Afghan district governor along with his two bodyguards were killed mistakenly by NATO-led Australian troops in southern Afghanistan while five police officers and three Taliban militants were killed in a clash and a roadside bombing, officials said Thursday.

Rozi Khan Barekzai, governor of the Chora district in Uruzgan province, was called Wednesday to a friend's house in Trin Kot, the provincial capital, because the friend believed his house was surrounded by Taliban militants, said Gholub Wardak, the province's deputy police chief.

"Actually the man's house was surrounded by Australian forces, and when Rozi Khan and his men arrived there, the foreign forces mistook them for Taliban and opened fire at them," Wardak said.

He said Barekzai and two of his bodyguards were killed and two other bodyguards were wounded.

Barekzai, who was a mujahedin commander during the war against Soviet forces in the 1980s, had also served as provincial police chief after the fall of the Taliban regime in late 2001.

The NATO-led International Security Assistance Force (ISAF) said from Kabul that it was investigating an incident in which their forces were involved in a firefight in the province, but it was unclear if it was the same one.

About 1,000 Australian troops are stationed in Uruzgan. The soldiers are part of 53,000-strong ISAF force deployed to Afghanistan from 40 countries.

Afghan President Hamid Karzai was saddened by the killing of Barekzai, his office said.

The district governor was killed in a "misunderstanding" between the troops and local forces, a presidential statement said.

Meanwhile, a police commander along with two police officers were killed and another was wounded Thursday in the Kaftar area of Trin Kot when their vehicle was blown up by a roadside bomb, Wardak said.

In a separate attack on police, two more constables were killed and three were wounded Thursday when Taliban militants attacked their outpost in the south-eastern province of Paktika, provincial Governor Mohammad Akram Khepilwak said.

The poorly trained and equipped police forces bear the brunt of Taliban attacks because, unlike the Afghan army and international troops, they are present in all remote areas of the country.

More than 720 Afghan police personnel were killed in Taliban attacks in the first six months of the year, according to the Interior Ministry. More than 900 police were killed in violence in 2007.

In another incident, Afghan army forces clashed with a group of Taliban militants in the Arghandab district of the southern province of Zabul, killing three militants, the Defence Ministry said.

A US-led coalition soldier, meanwhile, died Thursday in eastern Afghanistan from a non-battle injury, the US military said in a statement.

The statement did not reveal the nationality of the dead soldier, but most coalition troops are Americans.

More than 4,000 people - mostly insurgents - have lost their lives in the conflict so far this year in Afghanistan. (dpa)