Three British troops killed by U.S. bomb

A U.S. warplane has mistakenly dropped a 500-pound bomb on British troops after they called for air support in Afghanistan, killing three soldiers and seriously wounding two others in an accident that could reignite debate about America’s heavy use of air power.

“Friendly fire” involving U.S. troops has killed three British servicemen in the Iraq war, but the incident Thursday was the first confirmed case between the two forces in Afghanistan. British officials were investigating the error, which comes amid growing concerns about civilian deaths from U.S. airstrikes.