A bus collided with a train in northern India on Friday, killing at least 16 people, including nine children on their way to school, police said.

The accident took place shortly after 8 a.m. (0230 GMT) in the Punjab state's Moga district, 380 kilometers (236 miles) northwest of New Delhi, when a small bus collided with a train, according to local police superintendent L. K. Yadav

Yadav said 16 people, including the nine schoolchildren, were killed in the accident. Another 16 were hurt, including three children. Police had earlier said 18 people died in the crash. Yadav did not explain the discrepancy.

Police said investigators were still trying to figure out if all those killed were passengers on the bus or if some had been on the train.

The general manager of Northern Railways, Sriprakash, who goes by one name, said poor visibility caused by foggy weather was responsible for the accident.

"This is the mistake of the bus driver," he told the NDTV television station. "Apparently there was fog and visibility was low."

Accidents caused by reckless driving, aging vehicles and bad roads kill tens of thousands of people every year in India.