CAMP DWYER, Afghanistan: Thousands of US Marines deployed in Afghanistan’s Taliban heartlands in an air and ground assault that marked a high-risk test of President Barack Obama’s new war plan.

Dozens of aircraft ferried out nearly 4,000 US forces from various bases before dawn, aiming to take the fight deep into the insurgent bastions of Helmand province in the country’s south ahead of Afghan elections next month.

It was the Marines’ first major operation since they deployed recently as part of 21,000 US reinforcements pledged by Obama in an aggressive US strategy to turn the tide on the 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.

Several hours into the Marines’ biggest battle since Fallujah in Iraq in November 2004, the only US casualties listed were two concussions from an improvised explosive device in Nawa district towards the border with Pakistan.

“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 AFP.

Operation Khanjar (Strike of the Sword), also involving about 650 Afghan police and soldiers, would bring security to the Helmand River valley ahead of Afghanistan’s presidential elections on August 20, commanders said.

A fleet of helicopters lifted about 300 soldiers from a camp called Dwyer at dawn with their commander confident they would have cleared a key road, secured a bridge and met with 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 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.

The first highly aggressive phase of the operation was set to last 36 hours, commanders said.

The troops were to push south down the Helmand River valley, deep into insurgent-held areas where international forces have failed to establish a presence despite ousting the Taliban from power in 2001.

Military commanders said Operation Khanjar would persuade local people 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 US strategy, he stressed that the security needs of Helmand’s residents came before killing Taliban.

“One of the most critical things is to tell people why we’re there, and we are going to have a limited opportunity to gain their trust,” Nicholson said.

“Our actions will allow voter registration in areas where there has been none,” he told commanders and embedded reporters.

Key targets of the air and land assault include the districts of Nawa and nearby Garmsir, where many of the insurgents are said to take refuge and produce the opium that funds militants.

Officers walking through the battle plan on a large floor map said they expected to find 300-500 Taliban fighters in Nawa district.

They also spoke of the key role that would be played by teams clearing roads of improvised explosive devices — favoured weapons of the militants.

Unmanned aerial surveillance would keep watch overhead while loudspeakers would keep local people informed, they said.

Brigadier General Muhayadin Ghori, the senior Afghan general involved in Operation Khanjar, told the same briefing that he was hopeful of success.

But he warned that any repeat of the civilian casualties that have undermined the reputation of Western forces among Afghans would be disastrous.

“One casualty of a child will give everyone a bad name,” he said. “We should give priority to civilian casualties and then look after our own wounded soldiers.”