A "major incident" has been declared by police after reports of an explosion in Leicester.

At around 7.03pm Leicestershire Fire and Rescue received calls from the public who said they had heard a blast on Hinckley Road.

All four casualties have been taken to Leicester Royal Infirmary, the ambulance service said in a tweet.

It said: "We have taken four patients to the Leicester Royal Infirmary at this stage @Leic_hospital Ambulance crews, our HART and @EMICS Drs remain on scene."

A hazardous area response team and ambulance crews remain at the scene in Hinckley Road in the west of the city, it added.

The University Hospitals of Leiceister NHS Trust confirmed four people have been taken to Leicester Royal Infirmary in a critical condition.

Leicestershire Police said people had been evacuated from businesses and homes in the immediate vicinity and taken to a nearby police station as a temporary measure.

A spokesman added that "at this stage there is no indication this is terrorist related".

A spokeswoman for Leicestershire Fire and Rescue said six fire engines had been requested and that the incident was being treated as a search and rescue operation.

Leicestershire Police tweeted: "There has been a major incident on Hinckley Road, Leicester.

"All emergency services are currently dealing with this. Carlisle Street and part of Hinckley Road have been closed. Please avoid the area."

Pictures and video on social media show what appears to be a shop on the street engulfed in flames visible from a distance.

The building appears to have stood next to a shop called TJ's Takeaway.

The fire and rescue service spokeswoman said at the time: "This is a search and rescue at the moment. It is unknown if people are injured or trapped."

She added that the affected property was a two floor building with a loft conversion that had suffered a "pancake collapse".

Video taken at the scene shows flames billowing into the night sky.

One clip filmed by Graeme Hudson appeared to show emergency services rushing to the aid of someone close to where the blast occurred.

Speaking to Sky News, Kat Pattinson who lives on the same road as the fire, said: "We are down the same street - about 500 metres from where the blast has taken place and our whole house shook.

"We checked on our children first and foremost and then we went outside.

"There is just an awful lot of smoke here at the moment and the whole area is cordoned off."

She added that the shop on fire is usually open until about 9pm on a Sunday, and has a flat above it.