Indonesian rescuers launched a search operation Sunday after losing contact with a passenger ship carrying more than 240 people in the Java Sea while it was traveling from East Java to South Kalimantan, officials said.

The Search and Rescue Office in Banjarmasin, the capital of South Kalimantan on Borneo island, said it received a report about two hours after contact with the Virgo Transport 8 was lost at around 2 a.m. Sunday.

The vessel had departed Surabaya, Indonesia's second-largest city in East Java province, for Banjarmasin.

"The ship's operator reported the incident to authorities after receiving information that the vessel had encountered bad weather," said I Putu Sudayana, head of the Search and Rescue Office, during a video briefing.

Initial information showed that the ship's last known position was in the Java Sea, about 148 kilometres (92 miles) from a pier in Banjarmasin.

According to the vessel's manifest, it was carrying 241 passengers.

There were no immediate reports of casualties.

The ship's operator, PT Virgo Yoel Rihi, reported the loss of contact and said the vessel had left Surabaya at 10:13 a.m. local time Saturday.

Following the report, a rescue team was deployed to the Basirih Search and Rescue pier in Banjarmasin, while a rescue vessel headed toward the ship's estimated last known location.

Sudayana, who is coordinating the search operation, said authorities were mobilising all available personnel and resources because of the large number of passengers and crew aboard the vessel.

He said the search was being conducted in coordination with maritime authorities and other relevant agencies, while officials were closely monitoring weather conditions in the area.