Five workers locked inside a burning supermarket in New York City early Saturday were rescued after firefighters broke down the doors, the fire department said.

The blaze broke out at around 3:30 a.m. (0730 GMT) at 101stAvenue and 102nd Street in the Richmond Hill neighborhood in Queens.

The five workers and 12 firefighters all suffered minor smoke inhalation.

According to initial investigation, the cause of the blaze was a propane torch used to remove floor tiles, and the owner of the Met Food location could be issued a summons for the device.

It was not clear if the workers were locked in for the night or if one of them had a key but was unable to use it, the fire department said.

The fire was under investigation.