At least six people were killed and 129 remain missing after a passenger ship capsized in Indonesia's Java Sea, while search and rescue teams continue efforts to locate survivors.

Indonesia's National Search and Rescue Agency (Basarnas) said 108 people had been rescued after the Virgo Transport 8 lost contact in the early hours of Sunday while sailing through rough seas.

The vessel was carrying 243 people, including 213 passengers and 30 crew members, when the incident occurred.

Ship overturned in rough weather

Transport Minister Dudy Purwagandhi said aerial observations by a rescue helicopter showed the vessel had capsized but had not completely sunk.

He added that the cause of the accident remains under investigation.

Basarnas had initially reported that the ship had sunk, but authorities later clarified that it was found overturned and floating upside down.

According to rescue officials, the ship lost communication at around 2:00 a.m. local time after encountering severe weather in the Java Sea.

The ferry had departed from Surabaya in East Java on Saturday and was bound for Banjarmasin in South Kalimantan.

Large-scale rescue operation underway

Indonesia's search and rescue agency has deployed rescue personnel, helicopters and multiple vessels to the ship's last known location.

The operation is being carried out in coordination with the navy, coast guard and other maritime authorities as crews continue searching for the missing passengers.

Some of those rescued have been transferred to nearby vessels before being taken to ports in East Java for medical treatment and further assistance.

Maritime accidents remain a recurring challenge

Indonesia, an archipelago of more than 17,000 islands, relies heavily on ferries and other forms of sea transport to connect its islands.

Passenger ferries remain one of the country's most affordable and widely used means of transportation. However, rough weather, challenging sea conditions and persistent maritime safety concerns have contributed to a series of deadly marine accidents in recent years.(ILKHA)