Eleven Indonesian fishermen survived after three days at sea clinging to their capsized boat, rescuers said Wednesday as they searched for at least 22 crew still missing after the weekend incident that left two dead.

The boat with at least 35 crew capsized on Saturday in waters off the remote Selayar Islands in South Sulawesi Province before the 11 were found stranded on two separate atolls after days floating in the sea.

Their boat capsized in bad weather during Indonesia's rainy season, according to the local search and rescue agency.

"They had been floating in the sea for three days, they were carried away by the current to Selayar waters," local government official Andi Caco Amras told AFP Wednesday.

The two victims were found on separate islands.

The fishing boat departed from a North Jakarta port on March 3 to Lombok Island in West Nusa Tenggara Province.

The navy and rescue volunteers were helping with the search efforts.

"The joint team will conduct a search and rescue operation and they have departed... this morning," local search and rescue official Andi Raswan told AFP.

He said it would take rescuers five hours to reach the location.

The survivors were found after local fishermen spotted them and alerted authorities, state news agency Antara reported.

Amras told AFP survivors said they held out for three days at sea by wearing life jackets and tying themselves to the boat.

"They were carried away along with the boat to the Selayar islands. The boat was turned over, the bottom was at the top," said the official.

The vessel of 93 gross tons was carrying "equipment to catch fish such as fish traps, nets, rocks, ropes, coconut leaves and fishing rods," he said.

Amras said 35 people were on the boat with 22 missing while the rescue agency gave a higher toll of 37 and 24 missing.

It is common in Indonesia for the number of actual passengers on a boat to differ from the manifest.

Authorities received reports about the incident early Tuesday but said bad weather had hampered their efforts.

Marine accidents are a regular occurrence in Indonesia, a Southeast Asian archipelago of around 17,000 islands, due to lax safety standards.

In 2018, more than 150 people drowned when a ferry sank in one of the world's deepest lakes on Sumatra island.