Elite US Marine reconnaissance teams were dropped behind Taliban lines by helicopter today as coalition forces stepped up operations in Afghanistan to break resistance in the besieged insurgent stronghold of Marjah.

Coalition forces in Afghanistan are to push forward with their anti-Taliban offensive, despite the deaths of 12 civilians and a British soldier.

Thousands of US Marines and hundreds of Afghan troops poured into villages of southern Afghanistan with armour and helicopters today in the first major operation under President Barack Obama's strategy to stabilise the country.

Four US Marines died in Iraq when their tank rolled off a bridge into a canal and they drowned, the military said today.