Pakistani officials say a bomb blast struck a bus Monday in restive Baluchistan province, killing at least three passengers and injuring 30.
Local media report the bomb was affixed to a motor bike and detonated by remote control.
Oil-and-gas-rich Baluchistan has been in the grip of a regional insurgency for years as separatist militants fight for more autonomy and greater control over natural resources.
The province bordering Iran and Afghanistan also is home to pro-Taliban militants.
Some information for this report was provided by AP, AFP and Reuters.