"Gas explosion 800 blk SUD multiple patients," the Plantation Fire volunteer group said on Twitter.
Plantation Fire Battalion Chief Joel Gordon was cited as saying by the WPLG news channel that at least 20 people were injured, two of them seriously.
The explosion reportedly happened inside a fitness centre.
Photos of the site showed a huge chunk of the shopping mall destroyed, with debris lying around in a wide radius.
The explosion shattered windows and damaged nearby buildings. Photos of the site showed a huge chunk of the shopping mall destroyed, with debris scattered around in a wide radius.
Police said they were working on what is believed to be a gas explosion. All stores and businesses in the area around the blast-ravaged Fountains Plaza were closed.