At least three people died and about a dozen were missing after an explosion at a block of flats in Jersey in the Channel Islands.
Emergency services arrived at the scene in St Helier in the south of the island following the blast, which occurred on Saturday at about 4am local time (8am UAE).
Police chief Robin Smith said firefighters were called to the area the night before after residents said they smelt gas.
Mr Smith said the blast was "devastating" and that there could be more fatalities.
"We have a three-storey building that has completely collapsed — described from a demolition point of view as a pancake that has dropped almost straight down," he said.
"There is also damage to a nearby building, another block of flats that the fire service needs to make safe. It is a pretty devastating scene, I regret to say."
When asked how many people were thought to be missing, he said it was "hard to properly assess the numbers" given the destruction of the building.
"We are looking in the region of around a dozen, currently," he said.
"That number could fluctuate, but that's the number we're operating to."
He said there could be more deaths.
Firefighters said they planned to search through the night for survivors.
"The plan is that we will continue searching. We have no other plan at this stage," said Chief Fire Officer Paul Brown.
"The area is being lit and teams will be working tonight, all night, and we will not stop for the time being."
Asked if the call the fire service responded to on Friday evening had anything to do with the cause of the explosion, Mr Brown replied: "I can confirm that the fire and rescue service did attend.
"I don't know the exact number of firefighters, but they did attend. The call was received at 20.36 yesterday evening.
"I know that they did conduct investigations, but I think at the moment what I'm focused on is just the emergency response.
"I will give you an answer to that but what I'd like to do for the moment is focus on the emergency response, talk to my colleagues and consider those bits that are subject to investigation - and make sure I don't tell you something that I need to tell someone else first."
The building is managed by Andium Homes and their chief executive was "working very hard to look after" those affected, Mr Smith said.
He said police would investigate "whether or not there was a safety issue" regarding gas supplies.
The operation was a "protracted incident" that could "go on for days, maybe weeks."
"It is a pretty devastating scene. The scene is a very dangerous one for all of our staff," he said.
Jersey's chief minister Kristina Moore expressed condolences for those who lost their lives and said residents displaced by the blast would be given alternative accommodation.
"This is going to take some days and we will keep everyone updated and fully informed, and we will do our very best to ensure everybody is properly looked after," she said.
The incident occurred near the harbour in St Helier.
A resident who lives across the bay from the block of flats hit by the explosion in Jersey said his bedroom was "shaken" by the blast.
Daniel Hunt, 19, a data administrator, said the blast woke him at about 4am.
"My bedroom was shaken from the explosion with the windows rattling, which was all very unnerving," he said.
"I went outside to take a look … I could see what looked like police and firefighters shining torches through windows of surrounding buildings.
"I assume as they were evacuating the surrounding area. The building [was] up in flames with smoke pouring out of the windows."
"To have this happen so close and so early in the morning you don't know what to think."
It caps a tragic week for Jersey, a British Crown dependency not part of the United Kingdom, whose economy relies on banking, tourism and fishing.
The coastguard on Friday abandoned a search for three Jersey fishermen missing for nearly 36 hours after their boat hit a freight ship.
Skipper Michael Michieli and two crew members went missing early Thursday when their 18-metre wooden vessel collided with the Commodore Goodwill off Jersey.
The fishing boat, L'Ecume II, sank in about 40 metres of water, too deep for divers to search without specialist equipment, the Jersey Coastguard said.
Fisherman William Jackson said he had known Mr Michieli since he was child.
"He's probably one of the most prominent fishermen on the island and in the community," Jackson told BBC Jersey.
"I was just shocked, absolutely shocked. The whole thing didn't make any sense really," he said, stressing that conditions were "perfect" when L'Ecume II had set sail.
The Commodore Goodwill, owned by Condor Ferries, remains docked in St Helier. Photographs showed large gashes on its prow.
Jersey is the largest of the Channel Islands, 20km west of the Cotentin Peninsula of France.
The island has a population of about 100,000 people.
