At least four people were killed and 12 were injured early on Monday when a gunman opened fire outside the Blue Parrot nightclub in Mexico's Playa del Carmen resort, during the BPM electronic music festival, organizers said in a statement.

The BPM organizers said three members of their security team were killed in the shooting, which it said was perpetrated by a lone shooter. There was no official confirmation of the death toll, and a Quintana Roo state government spokesperson said there would be a press conference later on Monday.

"We are overcome with grief over this senseless act of violence and we are cooperating fully with local law enforcement and government officials as they continue their investigation," BPM said in a statement posted on its Facebook page.