American forces in Afghanistan have opened fire on a vehicle killing four civilian aboard, including a woman and two children.

The incident happened in southern Kandahar city on Saturday when a US military convoy opened fire on the vehicle, which was passing, Shah Agha, a Kandahar police official told Reuters.

A statement from the provincial governor of Kandahar also confirmed the casualties.

Countless number of civilians have lost their lives since the 2001 US-led invasion of the country.

More than 1,500 civilians have been killed and many others wounded in the first six months of 2009, which shows a 24 percent increase compared to the same period last year, according to the latest UN report.

AGB/MMN