QUETTA - A hand grenade was thrown by unidentified men at the house of a Regional Manager Utility Stores Corporation (USC) in Sibi Town area here Wednesday in which no casualty was reported. According to police sources, unidentified armed men threw a hand grenade in the house of Regional Manager Utility Store Muhammad Akbar Shahwani which went off. The attacker fled from the scene after the incident. No loss of life was reported.  Police team reached the site and cordoned off the entire areas and started search to arrest suspects.