KANDAHAR, Afghanistan, March 12 (Reuters) - Western forces killed five Afghan civilians in an air strike in the southern province of Helmand, a tribal elder said on Monday. The elder, Meera Jan, said civilian houses were hit in the attack. As well as the five people killed, four were wounded, he said. A spokeswoman for NATO troops in Afghanistan said an air strike had been carried out in the Gereshk district of Helmand province late on Sunday but NATO forces were not involved. A spokesman for a separate U.S.-led force said he had no information about any air strike. Analysts say civilian casualties feed resentment of both foreign forces in Afghanistan and the Western-backed government. (Additional reporting by Saeed Ali Achakzai in SPINBOLDAK)