Four US soldiers were killed early Sunday by a homemade remote-controlled explosive device in Afghanistan's southern province of Kunar, US military and Afghan officials said, according to DPA. The soldiers were travelling in an up-armoured, high-mobility, multi-purpose wheeled vehicle in Kunar's Pech Valley when the incident occurred, according to a statement issued by US-led coalition forces in Afghanistan. The patrol was conducting route-clearance operations to keep the road open to civilian and military traffic, the statement added. Thousands of US-led coalition forces are currently hunting the remnants of the Taliban and their allies in the al-Qaeda network, mainly in southern and south-eastern regions of the war-torn country.