The driver and conductor of a bus that collided with a train at a railway crossing in the Koggala area of Habaraduwa have been arrested, police said.
Twelve people, including children, are receiving treatment in hospital following the accident, with one reported to be in critical condition.
Deputy director general of the Galle National Hospital, consultant Dr Priyantha Athapattu, said a child aged around 14 was in critical condition due to internal organ injuries and internal bleeding.
The child has undergone emergency surgery.
The accident occurred when the rear of the bus was struck by a train travelling from Beliatta to Maradana.
Police said the children had been returning from a visit to the Martin Wickramasinghe Memorial Museum in Koggala. They had travelled from the Kottawa area accompanied by tuition teachers and parents.
Preliminary investigations have revealed that 14 tuition teachers, six parents and 41 children were on board the bus at the time of the accident.
The railway crossing where the collision occurred is not equipped with safety gates and operates solely with traffic lights and an audible warning bell.
The 40-year-old bus driver and the 21-year-old conductor have been arrested in connection with the accident.