QUETTA - A police constable was killed while six people including a policeman sustained injuries in two incidents of bomb blasts in Hub and Basima areas of Balochistan on Friday. According to official sources, unidentified people hurled a hand grenade on a police vehicle Sakran Road in Hub which was on a routine patrol. A police constable Muhammad Azam and three civilians, identified as Imtiaz, Ali Madad and Nawaz Ali, sustained serious wounds. They were immediately rushed to Civil Hospital for treatment. The attackers escaped from the site after lobbing the grenade. Police has tightened security in Hub and started a search for the accused persons. Meanwhile, sources said a police constable and his two guests sustained injuries when a rocket exploded at a police station in Basima area of Washuk District. The rocket was fired on an FC checkpost in the area few days back but it was not exploded. It was brought to the police station where it exploded with a huge explosion on Friday. Police constable Abdul Rashid and his two guests sustained injuries. Later, the constable succumbed to his injuries. Meanwhile, unidentified people fired three rockets in Spain Kareez area of Quetta. No loss of life and property was reported. due to the rocket attack. Sources said the rockets were fired from the nearby mountains, which landed near a camp of Mari Gas Company in Spain-Karez area.