At least eight people are reportedly dead after a shooting in the early hours of the morning in the popular tourist resort of Playa del Carmen.
Witnesses say a gunman opened fire in the Blue Parrot club on the closing night of the BPM Festival, forcing revellers to flee in panic or cower in the toilets.
There have also been some reports of a second shooting at another BPM venue, The Jungle.
One of the first tweets on the incident was sent by renowned artist Jackmaster, advising people not to come to the venue.
Someone has come into the club in Playa Del Carmen and opened fire. 4-5 dead and many wounded. Stay in ur fuckin hotel if you're here at BPM
— JACKMASTER (@jackmaster) January 16, 2017
Video subsequently published on social media purportedly shows party-goers fleeing the scene of the attack.
All remaining events have been cancelled by the festival organisers following the attack. The authorities have yet to make any formal declaration on the incident.