The boat was on its way from Lombok island to Komodo island carrying 20 foreign tourists, four Indonesian crewmen and an Indonesian guide when it sank at about 7pm on Saturday night.
Ten people, including at least six of the foreigners, were rescued, said Budiawan, head of the search and rescue agency in Mataram, the provincial capital of West Nusa Tenggara, who like many Indonesians uses a single name.
Last night Budiawan said a search for the missing was under way, involving at least four ships
Among those rescued were two people each from New Zealand and Spain as well as tourists from Britain and France.
Last night the Foreign Office confirmed that two British citizens had been hospitalised, adding that they were ready to “offer consular assistance to any other British nationals who may be involved.”
Yesterday Suryaman, based on the island of Lombok, said that ten people had been rescued after the ship sank.
The vessel left Lombok on Thursday night and sank on Saturday about 7pm local time.
“We only received a report at 8am on Sunday,” said Suryaman, adding that poor communication caused a delay in deploying a search-and-rescue team.
He added: “The incident took place … when the boat hit a reef and sank.
“Fishermen managed to rescue five of them alive later at night on Saturday, and five other foreigners were rescued by a sailing boat.”
Accidents at sea have frequently occurred when migrant boats navigate the archipelago, but accidents involving tourist boats are rare.
A spokeswoman for the Foreign Office said last night: “We are aware that two British nationals have been hospitalised following an incident in West Nusa Tenggara, Eastern Indonesia, on 17 August. We are providing consular assistance.
“We are in contact with the local authorities about the incident and stand ready to offer consular assistance to any other British nationals who may be involved.”
She would not comment on the state of their injuries.
Last night information about the nationality of the survivors was vague but Tempo.co, a news website for Indonesia’s leading magazine, Tempo, reported that all 10 of those who were rescued were foreigners.
The wooden boat sank off Sangeang Api, a volcanic island in Bima district off the eastern coast of Sumbawa island.
Tempo.co quoted Abdul Wahab, co-ordinator for the search-and-rescue agency in Bima, as saying the boat was believed to be leaking when it sank.
Sutriyanto, another search official in Bima, said the number of people aboard the boat might have been higher than 25, given the absence of a manifest, according to Tempo.co.
Lombok is an island in the Indonesian archipelago, east of the island of Bali and is home to around 3.1 million Indonesians.