In one of the worst boat mishaps in Kerala in recent times, 15 school children and three teachers drowned as their boat capsized in a reservoir near Kothamangalam in Ernakulam district on Tuesday evening.

The joy ride, during an excursion by students of St Anthony's School in Elavoor near Angamally in the district to Thattakadu bird sanctuary, turned into tragedy as one of the three boats used be the students capsized, killing 15 students and three teachers, police said.

They said 106 students, 10 teachers and two non-teaching staff had set out for the excursion when one of the three boats ferrying them capsized.

The 15 students who met with a watery grave were all below 10 years of age, Ernakulam District Collector A P M Mohammed Hannish said.

Official sources late on Tuesday night confirmed the death of 18 people in the mishap.

The capsized boat was under repairs and none of the three boats had license to operate, the sources said.

It was a heart rending scene at various hospitals in Kothamanagalam and nearby areas as parents, relatives and school authorities rushed on hearing about the mishap.

The navy sent in a team of 12 divers and a medical assistant, naval sources said.

Chief Minister V S Achutanandan ordered an inquiry into the tragedy.

Schools in Ernakulam district will remain closed on Wednesday as a mark of respect for the dead, while Angamally town will observe a hartal.

The students, studying in 5th, 6th and 7th standard of St Antony's School in Elavoor in nearby Angamally had set out for the excursion at 7.30 in the morning in two buses, the school authorities said.

Some of the rescued children said at least 50 students were in the capsized boat.

Kerala Fisheries Minister S Sharma, told reporters that necessary instructions have been given to release the bodies without conducting postmortem.

Achuthanandan is expected to visit Kothamangalam on Wednesday.