Leicestershire Police said Sunday night that there are currently no indications of terrorist activity and businesses and homes close to the scene of an explosion have been evacuated.
"The incident will be the subject of a joint investigation with the fire service," the local police said on Twitter. "At this stage there is no indication this is terrorist related."
The blast destroyed a convenience store and a home in the downtown are of Leiscester City.
Carlisle Street and part of Hinckley Road in Leiscester City have been closed and local police asked people to avoid the area.
University Hospitals of Leicester NHS Trust tweeted that four patients taken to Leicester Royal Infirmary from the scene of the explosion are in a "critical condition."
Six fire engines were at the scene, Leicestershire Police said. Pictures showed flames rising from a building.
Residents living near a row of shops in the Hinkley Road, about 1.6 kilometers from the city centre, reported their houses shaking with force from a blast.
Leicester City is located in England's East Midlands region and about 140 kilometers from London.
Earlier, local police declare a "major incident" after reports of an explosion in the Hinckley Road area of Leicester.
At around 7:03 p.m., Leicestershire Fire and Rescue received calls from the public who said they had heard a blast in the Hinckley Road.
