KANDAHAR, June 7: A US soldier was killed and two others wounded after their convoy came under attack in Afghanistan's Uruzgan province on Monday, the US military said on Monday.

It said the incident happened when the soldiers' Humvee vehicle hit an "improvised explosive device" in Deh Rawud district of Uruzgan province, the scene since last week of a joint operation by US-led forces to protect elections due in September.

"All three were flown to Kandahar airfield hospital where the one soldier died," it said. An official in Deh Rawud, who did not want to be identified, said he saw US servicemen being taken by stretcher to a helicopter after the blast.

Uruzgan's governor Jan Mohammad Khan said the blast was set off by remote control by Taliban guerrillas. He said US troops called in air support and laid siege to Taliban positions after the explosion. "American forces have encircled the area and are not letting Afghan troops in there."

Uruzgan was one of the main strongholds of the Taliban regime before it was overthrown by US-led military in late 2001. Since then it has become a hotbed of Taliban guerrilla activity.

On May 29, four US soldiers were killed when their car hit a mine in an area of neighbouring Zabul province while three others soldiers were later wounded in the Kandahar region.

Khan said a total of 40 Taliban fighters were killed in a combined operation involving US and Afghan troops backed by US aircraft launched against the insurgents about five days ago in Uruzgan, Zabul and Kandahar provinces.

The aim of the US-led push is to destroy Taliban hideouts ahead of the landmark elections planned for September. Earlier on Monday, a spokesman for the US military in Kabul told a regular news briefing that US planes pounded insurgent caves after a gun battle between ground forces on Sunday in another area of Uruzgan.

He said there were no casualties among US forces in that episode. The Taliban have vowed to disrupt the elections, which have already been postponed due to lack of security.

Around 750 people have been killed in militant-related clashes across Afghanistan since last August, with most of the casualties in southern and eastern areas bordering Pakistan.

It has been the bloodiest period since the overthrow of the Taliban, despite the presence of about 20,000 US-led troops hunting militants across the country and some 6,500 NATO-led peacekeepers mostly stationed in Kabul. -Reuters