A boat carrying eight Singaporean tourists capsized just off Bintan Island in western Indonesia's Riau Islands province on Sunday, May 31.
Singapore-based news outlet AsiaOne reported that the passengers, which also included a nine-year-old child and six-month-old infant, were travelling on a scheduled tour of some nearby mangroves when their boat suddenly overturned in Bintan's Lagoi Bay at around 14:00 local time on Sunday.
The capsizing occurred amid strong currents and shortly after the waters off Bintan experienced a sudden heavy downpour.
The passengers later said that they became temporarily trapped underneath the boat after it overturned though all of them were able to safely reach a mangrove.
The eight passengers, the boat's captain, and a tour guide were eventually rescued by the crew of another boat that was also in the area at the time. Some of the rescued individuals were brought to hospital to be treated for minor injuries.
At least two passengers recounted that the captain was navigating the boat at high speed despite the rough sea conditions and that the boat had a maximum capacity of only eight people.