New Delhi - At least eight schoolchildren drowned when a boat capsized in a river in India's southern state of Kerala, police said Thursday.

The accident occurred in the Chaliyar river in Mallapuram district some 340 kilometres north of state capital Thiruvananthapuram on Wednesday evening.

The victims, seven boys and one girl, were all aged between 15 and 17 years.

"About 30 students from a state-run school were crossing the river to return home when the boat capsized mid-way," Raveendra Nath, a police inspector at the local police station said over the phone.

"Eight children drowned, while two are being treated at a hospital. The others managed to swim to safety or were rescued by locals," he said.

A girl who swam to safety told local media outlets that the boat was overcrowded.

"The oarsman had warned that the boat was overloaded. When the boat reached the middle of the river, water started seeping into the boat and it soon turned upside down," Jojina (who uses only one name) told the IANS news agency.

"While many of us swam to the banks, some of the students got help from locals who immediately came to our rescue," she added.

The accident occurred just a month after the state's worst tourism tragedy when a double-decker boat with tourists capsized in Thekkady lake, claiming 45 lives.

The southern state is a popular holiday destination for both domestic and foreign tourists.

Kerala Chief Minister VS Achuthanandan ordered the district authorities to conduct a probe and submit a detailed report.

"We will do all we can to help the bereaved families. All aspects of the accident will be looked into," Achutanandan told reporters. (dpa)