Johannesburg - Gauteng police have launched a manhunt for a gang of armed robbers who shot and killed a 36-year-old police officer in Vosloorus on Wednesday morning.The officer was shot in the upper body at about 07:30, spokesperson Major Mack Mngomezulu said on Wednesday afternoon."His colleague was not injured but traumatised and he has been taken to the local hospital," he said.The officer was shot at Vosloorus Crossing Mall. While patrolling the area, the officer and his colleague noticed the suspects coming out from one of the shops after committing an armed robbery.A shoot-out ensued between police and the group, which had allegedly stolen several goods including laptops and computers."Other suspects came from behind [and] shot and killed a policeman," Mngomezulu said.Police are searching for six men who fled the scene in a silver Nissan Tiida and white Audi A4.Mngomezulu said a Nissan Tiida was found abandoned at Vosloorus extension two."Police are also still looking at the CCTV footage to identify the killers."No arrests have been made.