The boat was bringing tourists back from a visit to a mosque in the city of Ayutthaya, north of Bangkok, when it crashed into a pillar on the Chao Praya River at 4pm local time (10am BST), according to reports.
Distressing video of the crash shows passengers in yellow shirts desperately trying to get off the sinking vessel, as people on the banks throw safety rope and life jackets into the water.
