A bomb that partially exploded inside a car in Belfast city centre contained 60kgs (132lbs) of home-made explosives, police have said.
A masked gang hijacked a car at 21:30 GMT on Sunday, placed a bomb on board and ordered the driver to take it to a shopping centre.
It exploded as Army bomb experts prepared to examine the car left at the entrance to Victoria Square car park.
No-one was injured. Police have blamed dissident republicans.
Northern Ireland's chief constable Matt Baggott said there had been a "surge in dissident republican activity" recently.
Last week, a bus driver was ordered to drive to a police station in Londonderry with a bomb on board.
On Saturday night, a van driver was threatened by two masked men and told to deliver a package to the same police station.
Mr Baggott added the public would see a "significant increase in police presence" in Belfast city centre over the next few weeks.
"We need people who have changed their minds and come into the peace process to give us information," he said.
Assistant Chief Constable Drew Harris said if the bomb had fully detonated while the driver was in the car "he would have been killed outright".
He said it was a "terrifying, shocking experience for the poor driver" adding that those behind the device were "very reckless."