Five people have died in an explosion at a shop in Leicester.
Residents said they heard “a big thud, like an earthquake” at the time of the blast in Hinckley Road at about 19:00 GMT on Sunday.
Five other people remain in hospital, one in a critical condition, Leicestershire Police said.
Supt Shane O’Neill said police believe there may be more people unaccounted for and rescue efforts were continuing on Monday.
- Live: Five dead in building explosion
At this stage the explosion is not being linked to terrorism, he added.
The building consisted of a shop premises on the ground level and a two-storey flat above.
Witnesses said the shop was formerly a Londis but recently became a Polish supermarket called Zabka. It is believed to have only been trading since the new year.
In a statement on its Facebook page, the shop said none of the usual workers were injured in the explosion “resulting in collapse of the entire building on our shop below”.
It added: “There was a boss on shift, who fortunately was slightly injured and is in the hospital.”
Matt Cane, group manager at Leicestershire Fire and Rescue Service, said the bodies of the five people were found during the search of the building.
He added fire crews were still working to find survivors who may be trapped in “voids” inside the collapsed building.
“When you look at the pictures of the building it looks incredibly unlikely that we would find anybody but we are absolutely committed to search and rescue at this stage,” he said.
“There are still pockets of fire in the basement area of the building.”
Rescue work was temporarily suspended at about 14:00 on Monday over fears for the stability of a neighbouring building.
Gas network Cadent said it had assisted emergency services on Sunday night by “isolating the gas supply” to the building and adjoining properties on Hinckley Road.
Supt O’Neill, from Leicestershire Police, said he “can’t say at this stage” what may have caused the explosion.
“It is a joint investigation between the fire service and the police and the priority is to make the area safe,” he added.
He urged anyone who knows someone who is missing to contact police, adding: “It is still a search and rescue operation. It is important we try and find as many people as possible.”
Tony Hartley, who lives near the blast site, said a group of men who ran to the scene to help the injured people.
“Me and a friend lifted up a steel girder with about five other blokes and removed a bloke from underneath it,” he said.
“We then turned round, saw rubble and heard a little boy crying. There was me and another bloke sifting through the rubble and we managed to pull the boy out.
“I said to him ‘Is there anybody else in there?’ and he said ‘My friend’s a metre back inside the building’ and that’s when the emergency services turned up.”
At the scene: BBC reporter John Alexander
There was a noise which sounded like the pilot light of a house boiler being lit, a loud whoosh followed by a tremor, like an earthquake.
At first I thought my boiler had exploded or my roof was falling in so ran outside, as did most of my neighbours. Then we were all asked to leave our houses.
I think the shop was usually open until about 22:00, most of the shops are convenience stores and takeaways along the road where the explosion was.
I tried to find out last night when we could get back into our houses and what they thought had caused the blast but they weren’t prepared to say. I was told we could return if we wanted at 04:30 and the power has been restored.
The road is still closed and there is a large plume of smoke coming from the building, the fire is still burning.
Angel Namaala, who lives opposite the shop, told the BBC she heard “this big thud, like an earthquake”.
She said: “The building had gone down and people were trying to help where they could by taking the bricks off. But the fire was getting bigger and bigger so people were told to leave the scene.”
Emergency service workers remain at the scene and are being offered drinks and food by a rapid relief team.
A 79-year-old resident, who lives nearby but did not want to be named, said a 15-year-old boy suffered head injuries in the blast.
“Someone brought him a duvet to keep him warm while waiting for an ambulance to arrive. Someone also brought him a stool from one of the houses and a chap was bandaging his head. I think he had a cut above his eyes and his back was hurt.”
Hinckley Road, from its junction with Bolton Road to its junction with Woodville Road, remains closed in both directions and motorists are advised to avoid the area.
About 28 properties in Hinckley Road were left without electricity following the explosion but power has since been restored, Western Power Distribution said.
Firefighters are expected to be on the site for “a number of days” and it was “still too early to say” what caused the explosion, Mr Cane added.