Police say a roadside bomb has wounded seven security personnel and two passers-by in southwestern Pakistan. District police chief Malik Arshad says the bomb went off Wednesday as vehicles carrying paramilitary forces and police were passing through Mastung, a town in Baluchistan province. Arshad has declined to speculate about who carried out the attack. Attacks on security forces in the region are routinely blamed on ethnic Baluch nationalists who are waging a violent campaign for more political autonomy and royalties from natural gas extracted in the province. The area lies south of the tribal areas bordering Afghanistan where Taliban and al-Qaida militants appear to be gaining strength.