QUETTA, Pakistan - A bomb exploded on a busy street in the southwestern Pakistan city of Quetta on Friday, killing a 4-year old girl and wounding 11 other people.

Quetta police officer Raja Mohammed Ishtiaq says The bomb was rigged to a motorcycle and it exploded outside a commercial bank. There was no immediate claim of responsibility. Police say four of the wounded were traffic police on duty nearby, and others were passers-by.

Quetta is the capital of southwestern Baluchistan province, where authorities have blamed armed tribesmen for bombings and attacks against the government.

Ethnic Baluch tribesmen are waging a low-level insurgency to press for greater provincial autonomy and control over natural resources in Baluchistan.