Dozens of frightened youngsters were evacuated from a Sheffield residential complex in the middle of the night after a van reportedly crashed into the side of it.
Witnesses told how a white van smashed through a barrier just metres below where about 40 children aged 16 and 17 were sleeping at The Anvil student accommodation in Clough Road, Sheffield city centre.
The vehicle is then said to have left the scene but the youngsters inside were reportedly placed in lockdown and not allowed to leave as a precaution following the collision at about 11pm last night.
Many of the youngsters were said to be staying at the accommodation as part of a week-long activity scheme organised by the National Citizen Service.
One parent, who did not want to be named, said they were told there had been a 'major incident' and mums and dads were advised to attend the building immediately to take their children home.
The mum said her son was inside the building when it happened and the incident caused alarm both for those at the scene and for parents back home.
She said: "My son said there had been a major incident and the building was on lockdown.
"In this current climate with extremists carrying out attacks you fear the worst and we were all worried as we didn't really know what had happened
"My son's dad went and got him straight away. He said some people did see a white van going through the gates and disappearing off.
"There were loads of police cars at the scene."
She told how the youngsters were due to take part in a five night residential stay at the complex organised through the NCS to teach young people about living independently, such as budgeting, cooking meals and getting to bed at a decent time.
But she added the scheme has now been cancelled.
"It is a great shame that this has happened because it is a really good scheme.
"We have been told the residential element has been cancelled but I think the NCS are looking to see if anything else can be done."
An onlooker took two pictures at the scene and sent them to our Twitter account.
The NCS and South Yorkshire Police have been contacted for comment and we are waiting for replies.