A Thai tourist nightclub caught fire early Friday, killing at least four people who were burned beyond recognition and injuring more than 20 others, AFP reports.

According to officials, the Tiger Pub experienced a blackout and the fire started at about 4.00 a.m. after the power came back with a loud explosion. The police are investigating whether the cause of the fire was a lightning strike or an exploding electrical transformer.

Tiger Group executive Tomrongsak Boonyarunk told AFP that the club was officially closed when the fire happened but about 70-80 people were seeking shelter from the rain. Authorities have not identified if the four dead who were burned beyond recognition were foreigners. The Tiger Group said it fully complied with law on fire exits but said that it would accept responsibility for the incident.

The Santika Club fire in 2009 killed 60 people, including foreigners, during New Year’s Eve celebrations. Thailand’s turbulent politics and devastating floods have hurt tourism in the country in recent years.