- Video report by ITV News National Editor Allegra Stratton
Worshippers tackled a knifeman in a mosque after he stabbed a man in his 70s who was leading the call to prayer.
A 29-year-old man, who is believed to have been attending prayers at London Central Mosque in Regent's Park, central London, was arrested on suspicion of attempted murder at the scene on Thursday.
The victim was taken to hospital, where his condition is said not to be life-threatening, and Scotland Yard is not treating the attack as terror-related.
The mosque said members of the congregation broke from their prayers and restrained the attacker until police arrived.
Mustafa Field, director of the Faiths Forum for London, told reporters outside the mosque that worshippers said it was "one stab, one strike, around the neck" of the victim.
He said: "Then the congregation members, some of them broke their prayers, and intervened, restrained the individual.
"The mosque security called the police, and the police were there within minutes, and he was restrained and taken away."
Witness Abi Watik, 59, told ITV News the victim had been stabbed once in the right shoulder moments after prayers had started.
Mayor of London Sadiq Khan said police would be providing extra resources, writing on Twitter: "I'm deeply concerned by this incident at London Central Mosque.
"Every Londoner is entitled to feel safe in their place of worship & I want to reassure London's communities that acts of violence in our city will not be tolerated.
The Met are providing extra resources in the area."