At least eight children drowned Wednesday when a boat carrying at least 35 students capsized in southern India, police said.

Rescue workers were searching for the other children and their fate was not immediately known, said Vasudev, a local police official who uses only one name.

The cause of the accident was not known, he said.

The accident occurred on the Chaliyar river in the Malappuram district of Kerala state, more than 1,300 miles south of New Delhi. Kerala is a popular tourist destination for both Indians and foreigners.

Boat accidents are common in India, where many vessels are unsafe and overloaded.

Last month more than 40 tourists drowned in Kerala after the double-decker boat they were traveling in capsized in a reservoir.