Londonderry car bomb exploded minutes after young people walked past, CCTV reveals

Dramatic CCTV footage has shown how a car bomb exploded outside a courthouse in Derry/Londonderry - minutes after a group of young people walked past the vehicle.

The Police Service of Northern Ireland (PSNI) released four video clips showing how the attack in Bishop Street unfolded on Saturday night.

The footage shows the car being parked outside the courthouse before the male driver is seen getting out the car and running away.

Seven young people are then shown walking on the pavement as they pass the parked vehicle, while four cars on the road overtake it.

Around 30 minutes later - when the street is quiet - the car explodes, sending a huge fireball into the air.

Police believe the New IRA may have been behind the attack.

Assistant Chief Constable Mark Hamilton said that was their "main line of inquiry" as he described the bomb as "crude" and "very unstable".

A Ford Fusion was hijacked from a pizza delivery driver by "at least two armed men" on Saturday night, he said.

After a bomb was placed inside, it was driven to the courthouse on Bishop Street where "a single man jumped out of the car and ran away".

Four people have been arrested in the city in connection with the explosion.

Two men in their 20s were detained in the early hours of Sunday morning, while another two men, aged 34 and 42, were held on Sunday evening.

Mr Hamilton said the car bomb was a "very significant attempt to kill people" and that using such devices was an "act of madness".

He described the New IRA as "small, largely unrepresentative, and determined to drag people back to somewhere they don't want to be".

The group - known as the Real IRA until 2012 - is a dissident republican paramilitary group dedicated to bringing about a united Ireland.

Mr Hamilton said people were evacuated "just in time" and that "the bomb detonated just as we were leaving the area".

The alarm was first raised after a call was placed to the Samaritans.

It went through to the charity's West Midlands branch as calls go to the first available operator around the UK. The Samaritans called West Midlands Police, who contacted police in Northern Ireland.

Mr Hamilton said the call meant there was "at least 10 minutes before the police here were informed that there was a bomb in the community".

The bomb was "to some degree effective", but it "wasn't so effective that it created widespread damage", he added.

Emergency services descended on Bishop Street in the Foyle area of the city following the explosion shortly after 8pm.

"This attack was unbelievably reckless," Mr Hamilton said. "Thankfully the attackers failed to kill or injure any members of the local community out socialising and enjoying the best of what the city has to offer."

Michael Williams, who was in his house nearby, told Sky News: "There was a very large boom and everything started to shake for just a second as the shock passed over.

"Everything sort of shook, my desk was shaking, I was shaking, my chair was shaking."

Sky News' senior Ireland correspondent David Blevins said tension was "already high over the lack of a government and fear of the return of a hard border because of Brexit".