U.S. and Afghan forces are searching for a man who fired on a civilian helicopter in southern Afghanistan, killing the pilot and seriously wounding two other people on board.

The manhunt involving house-to-house searches was launched Sunday after the aircraft was hit by automatic gunfire, as it prepared to take off from a town 50 kilometers west of Kandahar, a former stronghold of the ousted Taleban.

U.S. military spokesman Lieutenant Colonel Bryan Hilferty says a person stepped from a crowd, opened fire with an automatic weapon, then fled the scene.

The pilot who died was a 45-year-old Australian man hired by the Louis Berger Group, an American company working on reconstruction projects. He was transporting people inspecting the construction of a health clinic when the attack took place.

An American woman and a British security guard on the helicopter were badly hurt, and taken to Bagram Air Base outside Kabul for treatment. An Afghan interpreter on board escaped serious injury.

A man claiming to be a spokesman for the Taleban called news agencies and said supporters of the ousted government were responsible for the attack.

The company that owns the helicopter is also working on rebuilding the highway linking Kandahar and Kabul. Crews on the road project have been the target of numerous kidnappings and other attacks.