Transcript for At least 1 dead after 'horrific terrorist attack' in London, says mayor

Also much more ahead. The breaking news, unbelievable to see this headline break overnight. Another terror attack in London. This is the fourth now in three months. The assailant using a van to target muslims leaving a mosque. At least one dying, ten injured. London's mayor calling it a deliberate attack. Terry Moran is on the scene. Terry, good morning. Reporter: Good morning, David. We are in the north London community of finsbury park and behind me here you see this grimly familiar scene, the police cordon behind them investigators at the scene of this latest terror attack. That white van rented van right around the corner slammed into a crowd but this time the victims were people emerging from their nighttime prayers, the hatred directed at ordinary British muslims. Overnight terror strikes London again, at least ten injured and one dead on the scene possibly unrelated to the attack. A crowd of worshippers leaving evening prayers targeted in a malicious attack. At 12:15 A.M. Authorities already calling it a major incident. A white van on seven sisters road in north London suddenly accelerating veering off the road ramming into the pedestrians leaving behind a trail of broken and bloodied victims and bystanders wrestled the suspect pinning him down until officers arrived. He asked why did you do that, why, you know, innocent people. He goes, I want to kill muslims. Reporter: Within minutes police and emergency crews were swarming the scene shutting down the scene. People tended to the injuring administering chest compressions at the scene. It started as a night of worship. Mosque members are seen here just moments before their night of prayer turned deadly. Horrified nearby residents described a scene of carnage. This latest incident comes as the city of London is still on edge. Officials now call this a terror attack. And it is the fourth terrorist attack in great Britain this year. Just two weeks ago a white van driving on a London bridge plowed into pedestrians, the attackers then going on a deadly stabbing spree. This morning, prime minister Theresa may saying this is a terrible incident. All my thoughts are with those who have been injured. After that van came to a stop right back there, the driver, the alleged aing thatter was grabbed and pinned to the ground and some in the shocked and angry crowd with calling for blood until a local Imam said hand it over to police and that probably saved this alleged attacker's life. The situation growing more

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