Kabul, Aug 25 (DPA) Four US soldiers were killed Tuesday by a bomb while on patrol in volatile southern Afghanistan, military officials said.

'They were struck while patrolling in one of the most violent areas of Afghanistan,' Brigadier General Eric Tremblay, a spokesman for the NATO-led International Security Assistance Force (ISAF), said in a statement.

A US military spokesman, Navy Chief Petty Officer Brian Naranjo, confirmed the ISAF soldiers who died were Americans.

Before this latest attack, 59 foreign soldiers had been killed in August in Afghanistan, according to icasualties.org, a website that tracks casualties in Iraq and Afghanistan.

The most violent month in the Afghan conflict for international forces since the 2001 fall of the Taliban was in July when 76 foreign soldiers were killed.