A man in an Afghan army uniform has opened fire on US-led soldiers at Kandahar airport in southern Afghanistan, an official says, adding that casualties are feared.

"One of our soldiers opened fire on NATO soldiers in Kandahar airport this morning, casualties are feared," General Abdul Hamid Wardak said Monday, quoted in a Xinhua news agency report.

The Afghan officer said that an investigation has been launched into the incident to determine the reasons behind the move or any casualties.

The incident came as the fighting between Afghan soldiers and Taliban militants has finally ended hours after the attackers launched their assaults on the capital Kabul and other areas in the country.