QUETTA - Five people, including a Punjabi labourer, were killed in firing and hand grenade attack in the provincial capital Monday. According to police, four people were killed when unidentified armed motorcyclists opened indiscriminate fire on them in Eastern Bypass area. The deceased were shifted to hospital. However, their relatives did not allow the police to conduct autopsy and took the bodies. The deceased were identified as Abid Khan, Abdul Hameed, Nihal Khan and Saadullah from the Bugti and Rindh tribes. The police said investigation was underway to ascertain the reason for the killings and land dispute might be the motive. Separately, a Punjabi labourer was killed and another wounded in a hand grenade attack. Unidentified armed motorcyclists lobbed a hand grenade at a house at Killi Alamu in the outskirts, which exploded killing labour Sohaib, a resident of Sadiqabad, Punjab, and wounding another. Police reached the site and moved the deceased and injured to hospital. Labourers were sleeping in their room when they came under attack, a police officer said. No group claimed responsibility for the attack till filling of this report. Police sent the body to his native town after completing legal formalities. Meanwhile, the police arrested more than 150 suspects in connection with the murder of three policemen, including of the New Sariab SHO. Unidentified armed men shot dead SHO Manzoor Tareen and two constables when they were passing from Killi Shahnwaz of Sariab Road Sunday night. Sources said more than 150 suspects were arrested in the raids carried out under supervision of DIG (Operations) Hamid Shakeel. According to an official, the police backed by the Anti-Terrorist Force and Frontier Corps were conducting raids after the incident. After investigation, innocent people would be released, he said, adding that arms were recovered from the detainees. Balochistan Chief Minister Aslam Raisani took notice of the killing and ordered immediate arrest of the culprits. Meanwhile, an FIR of the killing was lodged with the New Sariab Police.