An explosion took place in Ministry of Internal Affairs hostel in St. Petersburg on Enthusiast broad street, 39/1. Petersburg internet edition Fontanka.ru informs one man died; he was an assistant of operative orderly. Rinat Akhmetzyanov left the service six months ago. He was thrown out by air-blast from a window of a room on 10th floor. Informational RIA Novosti says the explosion took place in police hostel on Solidarnost broad street at the same time. According to preliminary version by a representative from North-West Emergency Control Ministry center the cause of the explosion was unknown explosive assembly. But Ministry of Internal Affairs said journalists the cause of the explosion in some flat of police hostel could be defective gas-cylinder. Fontanka.ru informs the explosion was nonrandom - former policeman committed suicide detonating a grenade. There is information that Akhmetzyanov sent SMS message to his sister with words "Adieu, I▓m leaving!" Colleagues of the dead say Akhmetzyanov was in Chechnya several times, was able to use every kind of weapon easily but could not find any job after he had left the service. This could be a reason of his suicide. He might take the grenade from Chechnya. Representatives from local police department and district office of public prosecutor are working at the site of occurrence. Reasons of the explosion are being cleared up.