Hundreds of hotel guests, 150 people attending an event in the Derry Masonic Hall and children from a local church youth club were among those evacuated by police prior to the detonation of a car bomb in the city centre on Saturday evening.
Assistant Chief Constable Mark Hamilton described the bomb attack as 'unbelievably reckless.'
“At around 7.55pm last night officers on patrol in Bishop Street spotted a suspicious vehicle and were making checks when, around 5 minutes later, information was received that a device had been left at the courthouse," he said on Sunday.
"We moved immediately to begin evacuating people from nearby buildings including hundreds of hotel guests, 150 people from the Masonic Hall and a large number of children from a church youth club. The device detonated at 8.10pm," he added.
The top police officer said officers believe the vehicles used in the attack was hijacked in the Brandy well.
"At this stage it appears as though the vehicle used had been hijacked from a delivery driver in the Quarry Street a short time before the explosion.
"This attack was unbelievably reckless. Thankfully the attackers failed to kill or injure any members the local community out socialising and enjoying the best of what the city has to offer.
"The people responsible for this attack have shown no regard for the community or local businesses.
"They care little about the damage to the area and the disruption they have caused. The area remains sealed off and church services at St Augustine’s has been moved to St Peters and the Cathedral services have been cancelled this morning as a result.
"We are incredibly grateful for the support and co-operation of the local community and I am appealing to anyone with information to please get in touch with us on 101. Information can also be given to Crimestoppers anonymously on 0800 555 111," said ACC Hamilton.