A bomb blast in Pakistan's southwestern Balochistan province on Thursday killed at least four people and injured 10 others. District Police Officer Syed Farid Ali said the bomb exploded outside a roadside hotel in Naseerabad, southeast of Quetta.He said the bomb was attached to a motorcycle parking in front of the hotel. The blast caused damage to the hotel and several other buildings and shops. Officials said those killed and injured are civilians. No group claimed responsibility for the blast. It is the fourth attack in Balochistan in less than a week.