An alleged suicide bomber was shot dead on Saturday during an encounter in which a policeman was critically injured, a Special Investigation Unit (SIU) official said on Saturday. The unidentified man restrained a private bank's security guard at gunpoint. He displayed twelve sticks of dynamite strapped to his waist and a grenade. SHO Nasir Mashwani said the man repeatedly warned the security guards and bank management he would blow himself up if anyone approached him. When police constable Muhammad Aslam tried to restrain him, the man opened fire, forcing a security guard and the policeman to shoot him. SIU chief SSP Raja Omer Khattab said he believed the man was trying to rob the bank and was not a trained militant.