British police declared a major incident on Sunday after an explosion destroyed a convenience store and a home in the central English city of Leicester.

Pictures and videos posted on Twitter showed flames leaping into the sky from the site, which was reduced to rubble.

"All emergency services are currently dealing with this," the police force said in a statement. "Please avoid the area."

The city's fire department said it sent six fire engines after reports of a large explosion and a building collapse.

"We got a call about an hour ago after reports of a large explosion and a building collapse," a firefighter in the city's fire department's control room said.

Police and fire officials said they could not comment on whether there were any casualties.

A picture used by the Leicester Mercury newspaper showed a blaze and the rubble of the destroyed building, which the newspaper said housed a convenience store and a flat above it.

"We heard an absolutely massive explosion. It was pretty frightening," the Mercury quoted an unidentified resident, who lives a few streets away, as saying.

"We went to look out of the upstairs windows and saw loads of smoke, and then a few seconds later massive orange flames."

The local ambulance service said it dispatched a hazardous response team to the site.