Indonesian authorities intensified a search Monday for 129 people who were missing after a ferry capsized in rough weather in the Java Sea on Sunday, resulting in at least six confirmed deaths.

The Virgo Transport 8 was carrying more than 240 people when its captain issued a distress call detailing that the ship was listing in seas with waves reaching up to 10 feet. The vessel was en route from Surabaya in East Java province to Banjarmasin in South Kalimantan province, on Borneo Island.

Contact with the ferry was lost around 2 a.m. Sunday. Approximately two hours later, authorities received information indicating the vessel had overturned in the Masalembo waters of the Java Sea, about 92 miles from Banjarmasin.

Aerial footage released by the National Search and Rescue Agency on Sunday showed the overturned ferry floating in choppy waters. On Monday, a coordinated search effort involving 17 ships, aircraft, and approximately 655 personnel from the military, police, and other agencies was underway, according to Mohammad Syafii, the chief of the National Search and Rescue Agency.

Specialized underwater teams and navy-operated underwater thermal drones have also been deployed to enhance search operations and expedite victim recovery. "We remain hopeful of finding more survivors," Syafii stated during a video briefing.

Search teams, aided by nearby tugboats and other passing vessels, managed to rescue 108 individuals and recover six bodies on Sunday.

The ship's manifest indicated a total of 243 people on board, including 213 passengers and 30 crew members. However, it is common in Indonesia for actual passenger numbers to differ from official manifests. The 390-foot ferry, constructed in Japan in 1987, was also carrying 89 vehicles. The cause of the accident remains under investigation.

Survivors recounted harrowing moments during the capsizing. One survivor, Ahmad Saudi, described the ferry as appearing overcrowded, with many passengers sleeping in hallways and common areas due to full cabins. Saudi recalled the ferry suddenly listing without warning, leading to widespread panic amid the rough seas.

Rescuers carry a body of a victim on a stretcher.

Saudi speculated that the ferry's balance might have been affected by trucks loaded on one side, leading to the rapid tilt. "The women staying in the economy-class cabins likely didn’t survive because the ferry listed so quickly," he said, adding that there were no immediate alarms or announcements, potentially leaving many in cabins with insufficient time to escape.

Another survivor, Faisal, who goes by one name, reported that he and 14 other passengers clung to a portion of the overturned ferry that remained above water. "After the ship listed, people panicked and rushed to the upper deck, but eventually the ferry rolled over completely," he said. "Fourteen of us were left stranded there."

Faisal described the group reciting the Islamic call to prayer while enduring exhaustion and rough seas. A wave later carried him toward a lifeboat, which aided his survival.

Indonesia, an archipelago comprising over 17,000 islands, relies heavily on ferries for inter-island travel. Ferry accidents are not uncommon, often attributed to lax enforcement of safety standards.