were met with small arms, mortar and rocket propelled grenade fire as they flew in helicopters over Taliban lines and dropped into the town. Fighting was still under way hours later, with U.S. Marine Harrier jets streaking overhead and dropping flares in a show of force.
Other Marines met heavy resistance as they fought to seize control of the mountains surrounding Dahaneh in the southern province of Helmand. Another convoy of Marines rolled into the town despite roadside bomb attacks and gunfire.
It was the first time NATO troops had entered Dahaneh, which has been under Taliban control for years. Casualty figures were unavailable due to security restrictions.
U.S., NATO and Afghan troops are working to protect voting sites around the country so Afghans can take part in the country's second-ever direct presidential election. Taliban militants have vowed to disrupt the elections, and attacks are on the rise around Afghanistan.
Marines said they had captured several suspects in Wednesday's push and seized about 66 pounds (30 kilograms) of opium, which the militants use to finance their insurgency. Troops hope to restore control of the town so that residents can vote in the presidential election.
The new offensive, named "Eastern Resolve 2," is designed to break the monthslong stalemate in this southern valley where the Taliban are solidly entrenched. By occupying Dahaneh, the Marines hope to isolate insurgents in woods and mountains, away from civilian centers.
"I think this has the potential to be a watershed," said Capt. Zachary Martin, commander of Golf Company, 2nd Battalion, 3rd Marines, who lead the assault.
The goal is to cut off the Taliban from a major rear base, and reclaim the area's main market district. It is hoped this would have a ripple effect through neighboring villages, making civilians more willing to cooperate with NATO forces. The Taliban levy taxes in Dahaneh and maintain checkpoints in the area, which serves as a main trading route through northern parts of Helmand, which produces 60 per cent of the world's opium.
"In the long term, it could have tremendous effects for the entire province," said Martin, who company is based in the nearby town of Now Zad.
A combined force of some 500 US and Afghan troops took part in the attack, which included helicopters, snipers, and women Marines brought in to deal with Afghan women during the compound-by-compound search conducted by Afghan forces that accompanied the Americans. Martin said the Marines had devised tactics to minimize civilian casualties in the densely populated area. He said troops would strictly limit the type of weapons they used and would stick to a "proportional response" when under fire.
Casualties have mounted as US and NATO troops ramp up military operations following President Barack Obama's decision to send thousands more American forces to Afghanistan to cope with the rising Taliban insurgency.
Last month, U.S. and NATO deaths from roadside and suicide bomb blasts in Afghanistan soared six-fold compared with the same month last year, as militants detonated the highest number of bombs of the eight-year war, according to figures released Tuesday. Three US Marines and a Polish soldier died in the latest attacks, setting August on course to surpass the 75 U.S. and NATO deaths from all causes in July.
Though roadside bombs target U.S., NATO and Afghan troops, the blasts have killed a record number of civilians this year as well. Nine Afghans riding in a vehicle died in a bomb blast Tuesday in Kandahar province, said Daud Farhad, a doctor at Kandahar's Mirwais hospital.
"The enemy has moved to increase the use of indiscriminate IEDs against our forces as well as the Afghan people," said U.S. Lt. Col. Todd Vician, a spokesman for the NATO-led force. He said IED attacks are up in part because of increased operations by NATO troops.
Afghan soldier deaths from IEDs are also up sharply, Azimi said, but had no figures. A roadside bomb in Zabul killed two Afghan soldiers Tuesday, said Lt Gen. Sher Mohammad Zazai. At least 14 NATO troops, including at least seven Americans, have died in bomb blasts this month.