A gunman in the early hours of Monday opened fire at the BPM Music Festival in Mexico that killed at least five persons and injured nine.
Shots were reported at Blue Parrot club in the popular tourist resort of Playa Del Carmen, The Independent reported.
Jackmaster, a Scottish DJ playing at the festival, tweeted that people "should stay in their hotel rooms".
The festival has been going on for 10 years and is popular with foreign tourists, especially from the UK and the US. The 2017 event marked the festival's 10th anniversary.
A second shooting is believed to have happened at The Jungle club.
According to a witness, shooting began "literally two metres from us" in the club.
"We don't know if it's a terrorist attack or something else, but we were the first ones to hit the ground and watched it all unfold."
Media reports said the shooting may be connected to Mexico's ongoing wars between drug cartels.
(With IANS inputs)