One person was killed and 35 injured on Thursday in an explosion on a train in Pakistan's insurgency-hit southwestern Baluchistan province, a railway official said.
It was not immediately clear if the explosion, about 45 kilometres (25 miles) from the provincial capital Quetta, was caused by a bomb.
"One was killed and 35 people were injured in a blast on a passenger train," said Manzoor Ahmad Magsi, a railway official in Quetta.
The train was travelling from the southern port city Karachi to Quetta.
Gas-rich Baluchistan, which borders Iran and Afghanistan, is rife with militant and sectarian violence.
Hundreds of people have died since an insurgency flared in late 2004 in Baluchistan, where rebels are demanding political autonomy and a greater share of profits from the region's natural resources.
Pakistan has also recently been hit by a string of Taliban-related bomb blasts, as fears grow that Islamist extremists are exacting revenge for a six-week military offensive against them in three northwest districts.