Unidentified gunmen late Friday stormed two passenger coaches in southwest Pakistan, killing at least 19 people.

Unidentified gunmen late Friday stormed two passenger coaches in southwest Pakistan, killing at least 19 people, officials said.

"The attackers forced the buses to stop, abducted more than two dozen passengers, and then shot at least 19 dead," said Ismail Ibrahim, a senior official in troubled Baluchistan province.

The buses were en route to the port city of Karachi when they were stormed in Mastung district, according to Akbar Harifal, deputy district commissioner.

Harifal said security forces had rescued five passengers after an exchange of fire. It was unclear exactly how many passengers had been on the buses.

Sarfaraz Bugti, the province's home minister, later told AFP that 15 to 20 attackers armed with guns and other automatic rifles were involved in the attack.

No group has yet claimed responsibility for the attack but Baluch separatists demanding greater autonomy have been waging an insurgency for years and the province is also driven by sectarian strife and Islamist violence.