QUETTA, Pakistan (Reuters)

At least 13 people were killed and 25 injured in a bomb blast at a railway station in Quetta in southwestern Pakistan on Saturday, a police official told Reuters.

Pakistan is grappling with a surge in militant attacks in its northwest and a growing separatist insurgency in the south.

"The blast took place inside the railway station when the Peshawar-bound express was about to leave for its destination," said the senior superintendent of police operations, Muhammad Baloch.

No group has claimed responsibility for the blast.