Footage believed to be from a surveillance camera has emerged on social media, showing the final moments of the attack at London's Borough Market just before police converge and shoot the three suspects dead.

The video shows the final moments of the attack that started when the three men rammed a van into pedestrians on busy London Bridge late Saturday.

They then ran down a set of stairs and into the market, stabbing people at bars and restaurants as they went. Eight people died in addition to the attackers, and almost 50 others were taken to hospital.

The video shows a man crossing a deserted street in the market. One attacker runs up from the side and swings a knife at him, then the other two join in as he tries to run. The victim falls to the ground, and passersby appear to throw things at the attackers to try to stop them.