The family of the man held by police over the London mosque attack say they are "massively shocked" and "their hearts go out to the injured".

Darren Osborne, a 47-year-old who is believed to be a father-of-four from Cardiff, was arrested after pedestrians were targeted by a man driving a van near Finsbury Park Mosque in north London early on Monday.

#FinsburyPark Mosque attack: Suspect named locally as dad-of-four Darren Osborne https://t.co/ZKevlqw9EZ pic.twitter.com/qbqgGfShJt

— The Telegraph (@Telegraph) June 19, 2017

In a statement on behalf of the family, Osborne's nephew Ellis Osborne, 26, said: "We are massively shocked; it's unbelievable, it still hasn't really sunk in.

"We are devastated for the families, our hearts go out to the people who have been injured."

Osborne added his uncle was "not a racist" and said he had never expressed any racist views.

He added: "Its madness. It is obviously sheer madness."

The London Ambulance Service took nine people to three London hospitals. Two others were treated for minor injuries at the scene.

Witnesses described hearing a van driver, who was detained by members of the public at the scene, shout: "I'm going to kill Muslims."

The man was initially arrested on suspicion of attempted murder but Scotland Yard said he was later arrested for the commission, preparation or instigation of terrorism including murder and attempted murder.

Residents near Cardiff said they were "shocked" after seeing photographs of their neighbour being arrested in London.

In a telephone interview with ITV News, his mother described him as a "complex" person but said "that's all I can say".

The woman, who is not being named, broke down in tears.

She said: "It's a terrible, terrible shock."

Police have been searching a residential address in Pentwyn, where Osborne is listed as living.

Five residents identified images of the man being arrested as their neighbour, Osborne, who according to reports is originally from Somerset.

Neighbour Khadijeh Sherizi said: "I saw him on the news and I thought 'oh my God' that is my neighbour.

"He has been so normal. He was in his kitchen yesterday afternoon singing with his kids.

"He was the dad of the family. He has kids. He lives next door. He seemed polite and pleasant to me.

"I just can't believe it."

Scotland Yard said the attack unfolded while a man who had taken ill was receiving first aid from the public.

He was pronounced dead at the scene.

A spokesman said police investigations are "continuing to establish whether there is any link between his death and the attack".

The suspect remains in custody at a south London police station.