Thousands of U.S. Marines poured into Afghanistan's Taliban heartlands Thursday, launching the first major air and ground assault of President Barack Obama's challenging new war plan.
Dozens of aircraft ferried out the Marines from bases before dawn, aiming to take control of insurgent bastions of Helmand province in the country's south ahead of landmark Afghan elections next month.
Involving nearly 4,000 U.S. soldiers, it was the Marines' first major operation since they arrived in Afghanistan as part of Obama's aggressive new strategy to turn the tide on a dragging conflict with the Taliban.
"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," Marine commander Brigadier General Larry Nicholson said.
Around 10 hours into the Marines' biggest battle since Fallujah in Iraq in November 2004, Marine spokesman Lieutenant Abe Sipe said troops had encountered little resistance and suffered no major casualties.
"There has been sporadic and light resistance involving small-arms fire," he said. "They (the insurgents) are withdrawing after light resistance. The operation to stabilise and secure the Helmand Valley is going forward."
The operation called Khanjar, which means dagger in Dari and Pashtu but was translated by the Marines as 'Strike of the Sword', also involved about 650 Afghan police and soldiers.
The forces were to push south down the Helmand River valley, deep into insurgent-held areas where foreign troops have failed to establish a presence despite ousting the Taliban from power in 2001.
"Our aim is for us to be meeting local people within hours, and that's what we'll be doing for the next seven or eight months," Nicholson told news agency AFP.
In one small part of the operation, a fleet of helicopters lifted about 300 Marines from a desert camp called Dwyer at dawn, their commander confident they would have cleared a key road, secured a bridge and met villagers by evening.
"I told my men everything they have done to prepare for this operation means they are ready to go," said Captain Junwei Sun, 39, commanding officer of 2/8 Infantry Battalion's Fox company.
Afghan security forces were driving out to their targeted area, where the forces would meet, he said. "We expect to encounter resistance and come into enemy contact," the captain added.
Commanders said they would persuade locals that the Afghan security forces - backed by Western troops - offered them a better long-term future than the Islamist hardliners.
"This is a big, risky plan," Nicholson told his men at a briefing at Camp Leatherneck in the run-up to the battle's launch.
"It involves great risks and amazing opportunities. These are days of immense change for Helmand province. We're going down there, and we're going to stay - that's what is different this time."
Reflecting the new U.S. strategy, he stressed that the security needs of Helmand's residents came before killing Taliban.
Key targets of the air and land assault include the districts of Nawa and nearby Garmsir, where many insurgents are said to take refuge and produce the opium that funds their activities.
Officers walking through the battle plan on a large floor map said they expected to find 300-500 Taliban fighters in Nawa district.
Afghan army corps commander General Shair Mohammad Zazai told AFP the operation would establish security "so that people can go and vote with confidence and without fear".
Authorities have been concerned that the Taliban could undermine Afghanistan's second-ever presidential vote with violence and intimidation.
Khanjar appeared to be the biggest joint operation in Afghanistan since March 2007 when British forces led 5,500 troops in a campaign in Helmand.
But it was reportedly dismissed by the Taliban, with the Afghan Islamic Press quoting a spokesman as saying that previous operations had not yielded success for the armed forces.
"We are resisting but would adopt all kinds of war tactics to the situation," spokesman Yousaf Ahmadi was quoted as telling the agency.
The British military, which has proved unable to quell violence in its Helmand base, announced that two of its soldiers were killed in a blast that struck a separate operation north of the Helmand capital, Lashkar Gah.
The Taliban's Haqqani network claimed it had captured a U.S. soldier in what was believed to be the first such case in Afghanistan. The U.S. military confirmed one of its men was believed to have been captured.