Rescue workers in Indonesia said at least six people had died and 130 others were missing on Sunday after a ferry sailing between the islands of Java and Borneo capsized in bad weather.

Basarnas, Indonesia’s national search and rescue agency, said 107 people had been rescued from the Virgo ⁠Transport 8 vessel, which set sail on Saturday with 243 ​people onboard, including 30 crew members, ​from ‌the East Java ‌city of Surabaya.

The ferry’s last position before it lost contact at 2am on Sunday was in the Java Sea, about 150km (90 miles) from its destination, the city of Banjarmasin in South Kalimantan province, said Heri Purwanto, the head of the Banjarmasin port authority.

Indonesia’s transport minister, Dudy Purwagandhi, said the vessel had capsized. “From the information we received, based on helicopter surveillance … the ship capsized but has not sunk. As of 3pm [local time] it had not sunk yet, but it was capsized,” he said at a news conference in Banjarmasin.

The local search and rescue chief, I Putu Sudayana, said rescuers were battling waves of up to 2.5 metres (8.2ft) to reach the ferry. “It is extremely risky for vessels. Even our Basarnas vessel, which is 40 metres long, is at great risk,” he said.

A Basarnas helicopter had joined the operation, he said, adding that evacuees had been transported ⁠using a number of different ships and some of them would be taken to ​an East Java ​port.

Paramedics and ambulances were on standby in Banjarmasin, where dozens of relatives and friends of passengers checked a whiteboard on which the names of the rescued were being updated.

Jenah, 26, told Agence France-Presse she had come to the command post for information about her older brother. “I am saddened and very shocked. Until now, I haven’t received any more information,” she said. “He was travelling alone. I hope he survives. I couldn’t contact him since last night.”

Indonesia, an ​archipelago of ​more than 17,000 islands, relies heavily on ferries, with sea routes more affordable and readily available than air travel. However, safety standards are not always rigorously enforced, resulting in a relatively high accident rate.

On Monday, a speedboat carrying eight people, including five journalists working for local and international news agencies, went missing near a volcano, Mount Anak Krakatau, in Lampung province.

Last month, a fire onboard a ferry killed one person and left five others missing, while 211 were rescued, in the Lombok strait off the island of Bali. The ferry had been heading from Bali to the island of Lombok when it ran into trouble in the early hours of 12 August.

In July, a ferry transporting more than 70 people sank while sailing near Selayar, a small island south of Sulawesi.

Reuters and Agence France-Presse contributed to this report