Five members of the NATO-led international force in Afghanistan have been killed in a helicopter crash in bad weather in the country's south, according to coalition and provincial authorities.

Police in the southern province of Kandahar said the accident occurred on Monday evening during a heavy rainstorm in Daman district.

The NATO-led International Security Assistance Force (ISAF) does not release the nationality of casualties, but US, British and Australian soldiers operate in the country's south.

"The cause of the crash is under investigation. However, initial reporting indicates there was no enemy activity in the area at the time," ISAF said following the incident.

Helicopter crashes are fairly frequent in Afghanistan, where the 100,000-strong international mission relies heavily on air transport.

"There was bad weather in the area and the helicopter crashed at about 10pm," General Abdul Razeq, the Kandahar provincial police chief, told AFP.

"No insurgents were there at the time."

Separately on Monday, US troops have shot and killed two Afghan civilians as their truck was approaching an American convoy on the outskirts of Kabul, Afghan officials said.

Mohammad Alim, a commander for Kabul highways, said "a coalition convoy fired on a truck which was driving beside the convoy, which martyred two people and wounded another one".

Afghani Interior Ministry spokesman Sediq Sediqi said the victims in Monday's incident were employees of a company that repairs police vehicles.

Earlier on Monday, two US soldiers were killed and 10 wounded in a suspected insider attack in the eastern province of Wardak by a man in an Afghan army uniform who also killed several Afghan soldiers.

The NATO mission in Afghanistan has been unsettled this week by comments from Afghan President Hamid Karzai accusing the US of colluding with the Taliban to justify the presence of foreign troops in the country.

Washington abruptly rejected the allegations, saying the US has "spent enormous blood and treasure in supporting the Afghan people and did not support any kind of violence involving civilians”.

PHOTO CAPTION

Map locates Kandahar city in Kandahar province, where a helicopter crashed killed five U.S. troops.

Al-Jazeera