Johannesburg - A 50-year-old security guard was stabbed to death when he tried to stop two robbers at a mosque in Fordsburg, police said on Thursday.Two men broke into the mosque in the early hours of Monday morning and stole power tools such as grinders and drills, Johannesburg central police spokesperson Warrant Officer Xoli Mbele said. On their way out, the security guard confronted them in Mahlathini Street. One of the men ran away, while his accomplice carrying the bag of tools attacked the guard. CCTV footage, which was posted on social media, shows the alleged thief stabbing the guard several times. The guard tried to fight back. After his attacker ran away, he staggered a few steps before collapsing in the road.He was declared dead on the scene. No arrests had been made and a case of murder was opened.