MUMBAI, India (AP) — Nine people were killed after a fire broke out before dawn Wednesday on a train traveling from India’s financial capital of Mumbai, a railway official said.

Western Railways spokesman Sunil Singh said the fire broke out just after 2:30 a.m. and spread to three of the train’s coaches before the train was stopped and the fire extinguished.

Authorities are trying to determine what caused the fire to start a couple hours after it left Mumbai on its 48-hour journey to the Himalayan town of Dehradun.

The tragedy happened less than two weeks after 26 people were killed in another train fire in the southern state of Andhra Pradesh.

Accidents are common on India’s railroad network, one of the world’s largest, with some 18 million passengers daily riding on about 11,000 passenger trains. Most collisions and fires are blamed on poor maintenance and human error.