Four Tajiks were killed when a civilian helicopter contracted to carry supplies to foreign forces crashed in southern Afghanistan due to technical problems, officials said on Sunday. The helicopter went down in Shinkay district of Zabul province late on Saturday killing all on board, deputy provincial governor Mohammad Jan Rasuli told AFP. “Last night, a civilian helicopter contracted by (NATO’s International Security Assistance Force) went down due to technical problems,” he said, adding that the crew were from Tajikistan. An ISAF spokesman confirmed the crash and that the helicopter was contracted to deliver supplies to foreign forces in southern Afghanistan. He added there was no hostile activity reported in the area. Helicopter crashes have caused heavy casualties to international forces in Afghanistan, who are fighting a Taliban insurgency. Six US troops were killed in a helicopter crash in the Musa Qala district of Helmand province in southern Afghanistan last month.