Rescuers are scouring the seas off the popular resort island of Bali, Indonesia, after a ferry capsized at around midnight with 65 people believed to be on board.

Dozens of passengers remain unaccounted for, while around nine search and rescue lifeboats continue to look for more survivors. 23 people have been rescued in the hours after the tragic incident, but four people have tragically died, according to the Associated Press.

The ferry KMP Tunu Pratama Jaya sank around half an hour after departing from East Java's Ketapan port, emitting a distress signal at 23.16pm. Six minutes later, it was seen drifting on its side in the dark choppy seas.

The search operation in Bali has had to battle these conditions to locate survivors from the ferry accident. When it sank, the ferry was carrying 53 passengers, 12 workers, and 22 vehicles.

Emergency responders described how many of the rescued had been found floating due to the difficult conditions, which involved fighting two-metre waves in the darkness.

The ferry, which was heading to Bali's Gilmanuk Port, is reported to have suffered a critical leak relating to its engine. It then experienced complete power failure and capsized minutes later.

Images from Bali show ambulances lining up on a local harbour, waiting for any further survivors. Meanwhile, the loved ones of those on board have gathered on the island to wait for news, many of them tearfully fearing for the worst.

Ferry accidents are frequent in Indonesia, an archipelago of more than 1700 islands that relies heavily on the mode of transport for everyday life.