Jakarta: At least four people were dead and dozens unaccounted for Thursday after a ferry sank on its way to the resort island of Bali, according to local authorities who said 23 survivors had been plucked from the water so far.

The vessel, KMP Tunu Pratama Jaya, went down approximately 30 minutes after departing Ketapang port in East Java. It was en route to Bali’s Gilimanuk port, a journey of around 50 kilometres, according to a statement from the National Search and Rescue Agency.

The ferry was carrying a total of 65 individuals -- 53 passengers and 12 crew members -- as well as 22 vehicles, including 14 trucks.

As of Thursday, two bodies had been recovered while 20 survivors had been pulled from the water, many found unconscious after drifting in turbulent seas for hours, said Banyuwangi police chief Rama Samtama Putra.

Search operations involving nine boats -- including tugboats and inflatable craft -- have been ongoing since the vessel went down on Wednesday night. Rescuers have been contending with waves reaching up to two metres (6.5 feet) and poor visibility during the night.