At least three persons were killed and 15 others injured when a passenger bus turned turtle here on Sunday morning. According to police, a Lahore bound speedy passenger bus coming from Karachi overturned near Sangi Bypass while trying to save a tractor trolley. As a result of collision three passengers were killed on the spot while 15 others sustained injuries. The locals, rescue personnel and police reached the scene of the incident and helped in the rescue operation. The injured were rushed to different hospitals of Pannu Aakil and Sukkur where according to hospital sources condition of several injured persons was serious.