'Major incident' as explosion rocks UK city of Leicester

Four people are in a critical condition in hospital and a fifth is being treated for injuries following an explosion that left a building in the English city of Leicester in flames.

Leicestershire Police initially asked the public to stay away from the road where the explosion happened while first responders tended to what was described as a "major incident."

The department said on its website about three hours later there was no indication the emergency was terror-related.

"The cause of the explosion will be the subject of a joint investigation by the police and Leicestershire Fire and Rescue Service," police said.

The incident on a crowded street near the Leicester city centre with a mix of shops and apartments was being treated as a search-and-rescue operation, the Fire and Rescue Service said. Six fire engines and hazardous material response team were deployed.

"The Polish shop next to the bus stop has blown up. Avoid the area. Roads closed and lots of sirens in attendance," one witness tweeted.

"Smoke everywhere."

Photos show a convenience store disintegrated by the force of the explosion, with flames consuming the wreckage.

Leicestershire Police say people are being advised to avoid the area.

Reuters / Newshub.