LONDON (AP) — UK counterterrorism police are searching for clues into an attack that left two people dead and three injured near London Bridge.

Police said Saturday a man imprisoned six years for terrorism offenses before his release last year stabbed several people on Friday before being tackled by members of the public and shot dead by officers on the bridge.

Neil Basu, London’s police counterterrorism chief, said 28-year-old Usman Khan was attending a program that works to educate prisoners when he launched the attack. He killed a man and a woman and injured three others just yards from the site of a deadly 2017 van and knife rampage.

Health officials said one of the injured was in critical but stable condition, one was stable and the third had less serious injuries.