A motorboat capsized on Tuesday after being hit by strong waves in the lower reach of the Chao Phraya River, and two girls aboard are still missing, police said.

The incident occurred on a 300-meter-wide section of the river in the central Pathum Thani province. Viroj Sukkasem, 17, said he and four girl students from the same school were on their way across the river to a local market to buy stationery.

Three of the students were rescued by a passerby when they struggled for lives. Police believe the operator of the boat has fled.

The Chao Phraya River, a major river in Thailand, runs through the central part of the country and empties into the Gulf of Thailand.