A man has been arrested on suspicion of attempted murder after a stabbing inside a central London mosque.

The victim, in his 70s, was injured in an attack at London Central Mosque, near Regent’s Park, which police are not treating as terror-related. He was taken to hospital by paramedics where his condition has been assessed as non-life threatening.

A 29-year-old man was apprehended by worshippers who broke from prayer to restrain him until police arrived.

In a statement, the mosque said the injured man was the muezzin, the person who makes the call to prayer, and he had been stabbed shortly after 15:00 GMT during afternoon prayer. The mosque’s director general, Dr Ahmad Al Dubayan said he had a brief phone conversation with the muezzin in hospital, who said he was « okay and feeling well ».

Ayaz Ahmad, an adviser to the mosque, said the stabbing « would have been life-threatening if it wasn’t for the worshippers ».

Images from inside the mosque showed a man wearing a red hooded top, jeans and with bare feet being pinned to the floor by police officers. One video showed a knife on the floor under a plastic chair. Mustafa Field, director of the Faiths Forum for London, told reporters the attack 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. »

Abi Watik, who witnessed the attack, said the arrested man had been seen at the mosque previously and the muezzin was stabbed once in the shoulder. « He was praying behind him [the muezzin] and then he stabbed him. « He was waiting for him I think to start praying. He was right behind him. » The 59-year-old added that the suspect « was silent the whole time ».

Dr Al Dubayan said: « We are so sad about what has happened and we hope it’s just one off incident, not related or motivated by any kind of hatred. »

Miqdaad Versi, from the Muslim Council of Britain, said: « It is deeply concerning that this has happened… Given other recent attacks elsewhere, many Muslims are on edge, » he said.

Police believe the attack was an isolated incident and have increased patrols around the area to « provide reassurance to worshippers and the local community ».

Ch Supt Helen Harpe said: « A 29-year-old man was arrested at the scene and he has been taken into custody. « The man is believed to have been attending prayers inside the mosque. « This incident has undoubtedly caused a great deal of concern and we are working as swiftly as possible to establish the circumstances. »

Prime Minister Boris Johnson tweeted he was « deeply saddened » by the stabbing and his « thoughts are with the victim and all those affected ».

Mayor of London Sadiq Khan said the Met Police would be « providing extra resources in the area » following the attack. « Every Londoner is entitled to feel safe in their place of worship, » he tweeted.