Police confirmed four people were killed and four others were injured after a large blast destroyed a building in the UK city of Leicester. The area is still cordoned off and rescue efforts to find more casualties are underway.

Emergency response teams rushed to the scene after the explosion at about 7pm local time. The fire department sent six fire engines to the scene of the large blast which destroyed a convenience store and a home. A local hospital said two patients were in a critical condition and four people had less severe injuries.

A spokeswoman for Leicestershire Fire and Rescue Service has confirmed a search and rescue operation is underway.

“This is a search and rescue at the moment," she said to the Leicester Mercury. “It is unknown if people are injured or trapped.”

Sixty homes have been evacuated as part of the emergency response and roads in the surrounding area have been closed.

"At about 7pm, we heard an absolutely massive explosion," a witness told the local newspaper. "It was quite frightening. We went to look out of the upstairs windows and saw loads of smoke, and then a few seconds later massive orange flames.”

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There are no indications the explosion is linked to terrorism, the police said on Twitter. A spokesperson for gas network operator Cadent said the cause of the blast is yet unknown. Electricity has been switched off in the area around the blast site.