US Marines captured a town centre from Taliban insurgents in the southern Afghan province of Helmand on Wednesday, their first large operation in Afghanistan since arriving to reinforce Nato troops last month.

Asked if the Marines had taken control of the government buildings in the centre of the town of Garmsir, US Marines spokeswoman Captain Kelly Frushour said: "Yes, we are in control of that part".

The United States is frustrated by the failure of some European Nato allies to come up with troops to join the fight against militants in southern Afghanistan and sent 3,200 Marines to bolster British, Canadian and Dutch forces engaged in daily battles there.

The US Marines began pushing into Garmsir early on Tuesday, securing routes into the town in the south of Helmand province, the world's biggest opium producing region and a hotbed of insurgent activity.

The Taliban responded with small arms fire and rocket-propelled grenades, but failed to inflict any casualties.

British troops began deploying to Helmand in March 2006, before which only a small group of US forces had been present in the vast, mostly desert province and Taliban militants had taken control of most of the towns and villages.

Since then, the British force has more than doubled to more than 7,000 soldiers, and helped by Afghan and other foreign troops, has taken control of most of the towns along the Helmand River which brings life to a strip of land through the desert.

The town of Garmsir has been the scene of frequent raids by Afghan, British and U.S. troops, but has hitherto eluded capture.

Of the 3,200 US Marines sent to Afghanistan, about 800 are involved in training Afghan security forces, regarded by the Afghan government and the international community as the long-term key to bringing peace to Afghanistan.

The remaining 2,400 Marines are a highly mobile force which the Nato-led International Security Assistance Force can rapidly deploy wherever they are needed. - Reuters