KABUL - Twenty-five foreign fighters, including Arabs, Chechens and Pakistanis, were killed and wounded by Afghan security forces after they crossed the border from Pakistan into Afghanistan's volatile east overnight, a government official said on Tuesday.Jamaluddin Badr, governor of eastern Nuristan province, said an operation had been launched to guard against insurgents seeking to launch retaliatory attacks in Afghanistan after al-Qaida leader Osama bin Laden was killed by US forces in Pakistan on Monday."As a result of the operation, 25 foreign fighters were killed and wounded," Badr told Reuters. "We have launched an operation to control border infiltration."