More than 40 people have been injured in an explosion at a restaurant in northern Japan, police have confirmed.

The blast occurred at the Izakaya Cherry Blossom restaurant in the city of Sapporo, with the building's walls collapsing as it erupted into flames.

Photos and videos from the scene show people running away as they feared for their lives amid huge flames and billowing smoke.

Firefighters can be seen arriving in one of the videos, while panicked passersby are heard in the background.

Roofs and windows from nearby buildings were shattered due to the impact of the explosion, The Mainichi reported.

“I heard a ‘bang,’ which sounded like thunder, and my condo was shaken,” a local resident in his 50s told The Japan Times.

Several people were rushed to hospital by ambulance following the blast. One person is in critical condition, according to fire department officials cited by The Japan Times.

Authorities were alerted to the explosion in Sapporo's Toyohira Ward neighborhood at around 8:30 pm local time on Sunday.

The cause of the explosion is currently unknown.

The area where the explosion occurred is located about 50 meters from a metro station. It is home to many popular eateries, bars, and shops.

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