United States Marines have launched a major offensive against the Taliban in Afghanistan.
Nearly 4,000 Marines are taking part in the assault, code-named Operation Khanjar (Strike of the Sword), in the lower Helmand river valley in southern Afghanistan.
They are being backed up by about 650 Afghan troops and police.
“What makes Operation Khanjar different from those that have occurred before is the massive size of the force introduced, the speed at which it will insert and the fact that where we go we will stay, and where we stay, we will hold …” Brigadier General Larry Nicholson said.
The valley along the Helmand river is largely in the hands of Taliban fighters who have resisted British-led Nato forces for years.
The US has sent 8,500 Marines to Helmand province in the last two months.
The number of US troops in Afghanistan will rise from 32,000 to 68,000 by year’s end.
President Barack Obama has declared the Taliban insurgency in Afghanistan and neighbouring Pakistan to be the main security threat facing the US.
Helmand is one of the Taliban’s main heartlands in southern Afghanistan and produces the largest share of the country’s opium crop which supplies 90 per cent of the world’s heroin.
Attacks by Taliban fighters are at their highest levels since the strict Islamists were driven out of Kabul by allied-backed Afghan opponents in 2001 after refusing to turn over Osama bin Laden in the wake of the September 11 attacks on the US.
US and Nato commanders have said they intend to deploy American reinforcements to seize Taliban-held territory in the south in time for Afghanistan to hold a presidential election on August 20.