Thirteen people were killed and 27 injured when a bomb attached to a two-wheeler went off at Ragailong near the Police Commando Complex in Imphal West district on Tuesday evening.According to official sources, unidentified militants targeted the place where security personnel and civilians were gambling ahead of Diwali.The injured were shifted to the Regional Institute of Medical Science and Hospital and Jawarharlal Nehru Hospital.Chief Minister Okram Ibobi Singh, Police Chief Y Joy Kumar and other officials were at the hospitals visiting the injured.