At least 23 people died in a fire at a bar in Mexico's southern port city of Coatzacoalcos, after what could have been an attack on the premises, authorities said.

The fire broke out on Tuesday night and killed at least eight women and 15 men, according to a statement posted on Facebook by the attorney general's office of the state of Veracruz.

Another 13 people were being treated at hospitals for serious injuries, the office added.

"The Attorney General's office strongly condemns what could constitute a devious attack," it said in the statement.