Four Afghan policemen and one American soldier have been killed in separate attacks by suspected Taleban insurgents in Afghanistan.

Officials say the policemen were killed when insurgents ambushed a regional police chief's convoy in southern Helmand province, Tuesday. They say the police chief, Shadi Khan of Deshu district was not hurt.

The U.S. military says the American soldier died when insurgents fired on a military patrol in central Uruzgan province Tuesday. A statement said the soldier was pronounced dead after being evacuated to a U.S. base for emergency medical treatment.

Taleban militants have stepped up attacks on U.S. and Afghan troops in recent weeks as weather conditions in Afghanistan have improved.