-- At least four people have been killed and another four injured in an explosion and fire in central England on Sunday, authorities said.
Emergency officials were still on the scene in Leicester, about two hours north of London, on Monday morning, searching a collapsed structure and investigating the cause of the explosion, police said.
At least one of the four hospitalized had serious injuries, according to authorities, who warned that there could be others who have not yet been accounted for. The structure, with retail shops on the ground floor and an apartment above, was completely destroyed.
The Leicester Police Department declared it a "major incident" and ordered the public to avoid the area.
"There are four confirmed fatalities at this stage and a number of people still undergoing treatment in hospital," Leicester Police Superintendent Shane O'Neill said. "The building consisted of a shop premises on the ground level and a two-story flat above it. We believe there may be people who have not yet been accounted for and rescue efforts continue in order to locate any further casualties."
"Once the site is deemed to be safe a joint investigation with Leicestershire Fire and Rescue Service will begin looking into the circumstances surrounding the incident, which at this stage are not being linked to terrorism," O'Neill added.
The cause of the explosion is still under investigation, fire officials said.
"We have six fire crews on scene, including a specialist search and rescue team who are supported by two search dogs, and this level of resourcing is likely to be in place throughout the day," Leicestershire Fire and Rescue Service Group Manager Matthew Cane said in a statement.
"The cause of the explosion and fire is still yet to be determined," Cane added, "and we will work closely with colleagues from the police as our inquiries into the circumstances continue today."
One witness told the Leicester Mercury that around 7 p.m. "we heard an absolutely massive explosion. It was pretty frightening."