At last 20 people were injured after a vacant pizza restaurant exploded in South Florida on Saturday, according to police.

Of the 20, two are said to have sustained serious injuries from the huge explosion that sent debris flying in the air and into adjacent streets, as far as 100 meters away.

The incident prompted the closure of roads in the area as emergency services rushed to save the injured.

Health workers said there were multiple people being treated at the scene of the blast, while others had been taken to hospital.

Social media users have posted photos online of the aftermath of the blast. In the footage, roads are seen covered in debris and ashes, with the said restaurant completely destroyed.