Four U.S. soldiers killed, Afghan war heats up

By Paul Tait

KABUL (Reuters) - Roadside bombs killed four U.S. soldiers in southern Afghanistan, the U.S. military said on Sunday, the latest deaths in an escalation of violence that has put pressure on coalition leaders over their war strategy.

Thousands of U.S. Marines and hundreds of British soldiers have been fighting major new offensives in the past 10 days in Helmand province, a Taliban stronghold and Afghanistan's biggest producer of the opium that funds the insurgency.

The assault by U.S. Marines, Operation Strike of the Sword, is the first major operation under U.S. President Barack Obama's new regional strategy to defeat the Taliban and stabilise Afghanistan, which holds a presidential election on Aug. 20.

It was launched with insurgency violence at its highest since the Taliban's austere Islamist government was ousted in 2001 by U.S. and Afghan forces for failing to hand over al Qaeda leaders wanted over the Sept. 11 attacks on the United States.

Violence has again flared across Afghanistan since the operation began on July 2, with attacks in traditional Taliban strongholds in the south and east as well as in relatively more peaceful areas in the north and west.

The Taliban backlash has put pressure on leaders in Washington and London, who say U.S. and other NATO-led troops have pushed back Taliban insurgents but that a lot of tough fighting remains to be done during the summer.

U.S. President Barack Obama told Sky News on Saturday that the United States and its allies would have to evaluate Afghanistan again after next month's presidential election to see what other military or development steps might be needed.