Bangkok ( CNN ) -- Four people have been killed in a fire that swept through a popular nightclub in the early hours of Friday morning on the Thai island of Phuket . It 's not known whether those killed were Thai nationals or foreign tourists , as the bodies were burnt beyond recognition , director of Patong Hospital , Bhumin Silapan , told CNN . Eleven others were being treated in the same hospital , including seven Thais and four French nationals . One of the French patients was in a serious condition with 40 % burns and receiving oxygen , Silapan said . Police are still trying to determine the cause of the blaze but the officer in charge of the case told CNN that it 's believed a transformer near the Tiger Pub , also known as Soi Tiger , on Bangla Road , Patong , caught fire . `` I am interviewing many witnesses so I ca n't conclude the exact cause until I gather more information and evidence , '' Lt . Colonel Jongserm Preecha said Friday . Unconfirmed reports stated the fire was caused by a lightning strike which hit the transformer , according to Agence France-Presse ( AFP ) , which quoted Phuket deputy governor Chamroen Tipayapongtada . Phuket is popular holiday resort for foreign tourists and the Tiger Bar is described by one online travel guide as `` one of the most popular places to have a drink in all of Phuket . '' `` Every single night the entire bar area of Tiger is packed with bar girls and tourists and it is like this throughout the night , '' according to a review on Phuket-Fever.com . Forensic experts were expected to arrive at the hospital Friday afternoon to identify the dead .
Blaze spread through popular nightclub in Phuket , Thailand , killing four . Forensic experts to identify dead who were burnt beyond recognition . Police tell CNN the fire broke out at a transformer near Tiger Pub . Phuket is a popular destination for international tourists .