At least 13 people have been killed after a fire in a Russian nightclub that reportedly started after a flare gun was discharged inside.Emergency services rushed to evacuate 250 people when the blaze erupted in the city of Kostroma in the early hours of Saturday (5 November).Regional governor Sergei Sitnikov said a further five people were slightly injured and received medical assistance.A criminal investigation has since been launched, and police are searching for the person who used the flare gun.