Officials in southwestern Pakistan say a bomb blast has hit a convoy of three buses, killing at least 19 Shi'ite Muslim pilgrims.

Authorities say 25 other people were wounded Sunday – some seriously – in the remotely-triggered explosion in Baluchistan province's Mastung district.

One bus was destroyed and another badly damaged.

Officials say the bus passengers were on a pilgrimage to Iran, a majority Shi'ite country and popular destination for religious pilgrims. Pakistan is a majority Sunni Muslim country.

There has been no claim of responsibility for the blast.

Baluchistan is home to militant groups, including pro-Taliban factions, and Baluch separatists fighting a low-level insurgency in hopes of gaining political autonomy and a greater share of the profits from the region's natural resources.