Five US troops fighting Islamist insurgents in southern Afghanistan were killed in a helicopter crash in bad weather, the coalition and provincial authorities said Tuesday. Police in the province of Kandahar said the Black Hawk helicopter came down late on Monday evening during a heavy rainstorm in Daman district, AFP reported. The NATO-led International Security Assistance Force (ISAF) does not release the nationality of casualties, but a Western military official who declined to be named confirmed that the victims were all US forces personnel.