Afghan police secure the site of a suicide bombing in Khost, south of Kabul, Afghanistan, Oct. 1, 2012. The suicide bomber was driving a motorcycle packed with explosives and rammed it into a patrol of Afghan and international forces, killing over a dozen people, including three NATO service members and their translator, official said. (Nashanuddin Khan/AP)

A suicide bomber wearing a police uniform detonated
an explosives-packed motorbike amid a group of NATO and Afghan forces, killing three coalition soldiers and at least a dozen Afghans on Monday in the southeastern town of Khost, officials said.

Among the dead were four Afghan policemen, including the commander of a special unit called the Rapid Reaction Force, and an interpreter for the NATO-led force.

The Interior Ministry said dozens of people were wounded, many of them civilians.

The Afghan and NATO forces were on a foot patrol when the bomber struck in front of a bank in a crowded part of Khost, near the border with Pakistan, officials said. The Taliban asserted responsibility for the attack, part of the latest spate of violence in Afghanistan.

A local official speaking on the condition of anonymity said the three dead NATO soldiers were Americans, who make up the bulk of the coalition force in Khost.

The attack came two days after two Americans — a soldier and a civilian contractor — were killed during an exchange of fire, apparently with Afghan forces. The clash, in which three Afghan troops also were killed, may have been a result of a misunderstanding, one Afghan official said, though U.S. officials disputed that assertion.

At least 51 foreign troops have been killed this year in “insider attacks” by rogue Afghan forces.