At least six people, including three children, have been injured when a car mounted a kerb and ploughed into a crowd of people outside a sports centre in Newcastle, according to reports.
Those affected had gathered at the Westgate Sports Centre to celebrate Eid al Fitr, which marks the end of Ramadan.
Hundreds of people were believed to be at the sports centre.
Northumbria Police said they arrested a 42-year-old woman following the incident, which is not believed to be terror-related.
"From what I understand, [a woman who had been at prayer] was about to leave in her car and I believe she lost control," an eyewitness told the BBC.
"I ran up straight away because everyone was moving in on all the injured, trying to put water in their mouths. The parents of the kids were there, I had to sort of try and calm them down just to tell them the ambulance is there and they will take care of it; they know what they're doing."
One of the injured children is said to have been in critical condition.
A North East Ambulance Service spokesman said: "We received our first 999 call at 9.15 this morning to report a car that had mounted the kerb.
"We have taken six people to hospital, they have gone to the Royal Victoria Infirmary in Newcastle, three children and three adults."
Chi Onwurah, Labour MP for Newcastle Central, said in a Tweet she was saddened by "the terrible accident".
"So sad, I was at the prayers earlier & there were so much joy & unity. Thinking of those affected by what I am told was terrible accident," she said.
The incident occurred days after one person died and another ten were injured after a man rammed a van into pedestrians outside a mosque in Finsbury Park, East London.
The victims were Muslim worshippers who had gone to the mosque to pray after Iftar, the breaking of the dawn-to-dusk fast observed during the month of Ramadan.
Police charged 47-year-old Darren Osborne with terrorism-related murder and attempted murder following the attack.