Marines, Afghan troops launch offensive in Helmand

An Afghan policeman stands guard along a street in Herat, western Afghanistan, August 11, 2009.

KABUL (Reuters) - Some 400 U.S. Marines and 100 Afghan army soldiers staged a helicopter assault on Wednesday in the mountains of Helmand province in Afghanistan, part of an effort to secure Taliban-held areas before August 20 elections.

Pentagon spokesman Bryan Whitman told reporters in Washington the force, part of the 10,000-strong U.S. Marine Expeditionary Brigade sent to Helmand, was "engaged in a fight, they are meeting some resistance." Whitman said he had no reports of casualties.

The fighting in Helmand coincided with the wounding of two Associated Press journalists embedded with a U.S. military unit in a roadside bombing late on Tuesday near Kandahar.

Photographer Emilio Morenatti, 40, a Spaniard based in Islamabad, Pakistan, suffered a wound to the leg that resulted in him losing a foot, while TV videographer Andi Jatmiko, 44, from Indonesia, received leg and rib injuries in the blast, the AP said.

Eighteen journalists were killed in Afghanistan between 1992 and 2008, making it the 11th most dangerous country in the world for media workers, according to the Committee to Protect Journalists.

Dozens of journalists have descended on Afghanistan to cover the country's presidential election. Taliban militants have vowed to disrupt the polls and the United Nations says spiraling violence threatens to keep many Afghans from voting.

The offensive in Nawzad, a district in northeastern Helmand, was an attempt to ensure "Afghans are going to have the freedom of movement to be able to go to polling places and be able to cast their vote and to do it in a secure and unfettered manner," Whitman said.

"An operation like this contributes to that goal of allowing Afghans the ability to exercise their right to vote," he said, adding the aim was to clear Taliban resistance in the area and then hold the territory to prevent.

The Marine brigade is the biggest element of a wave of reinforcements sent this year by President Barack Obama in an effort to turn the tide in an eight-year-old war commanders have described as stalemated.

Helmand has been the focus of U.S. and NATO effort since U.S. and British forces launched the biggest operations of the war last month. By far Afghanistan's most violent province, it produces the bulk of the world's opium poppy crop.

The period since the beginning of July has been the deadliest of the war for U.S., British and allied troops. More than 100 have now died since the beginning of July.

More Western troops have died since the start of March in Afghanistan than in the entire period from 2001-2004.

Thousands of British troops, who occupy other parts of Helmand province, launched their own operation Panther's Claw north of the provincial capital Lashkar Gah, facing the heaviest British ground combat casualties in a generation.

(Reporting by Peter Graff in Kabul and David Alexander in Washington, Editing by Phil Stewart)