Russia's FSB security service said it has "neutralised" a gunman who opened fire in central Moscow Wednesday and confirmed an unspecified number of casualties, in a statement carried by Russian news agencies. "An unknown individual opened fire near building number 12 on Bolshaya Lubyanka street, there are casualties. The identity of the criminal is being established. The criminal has been neutralised," agencies quoted the FSB as saying, without giving further details. The gunman opened fire with an automatic weapon in the entrance lobby of the FSB building, witnesses told the BBC. Security forces cordoned off the area and moved bystanders into nearby buildings. Russian media say shots have been fired in downtown Moscow near to the headquarters of the country’s national security agency, with at least one person believed to have died. Some reports suggested three officers had been killed after an assailant opened fire with a Kalashnikov assault rifle. The shooting came hours on the eve of Day of Security Services<em><strong> </strong></em>when law enforcement and soldiers get a special holiday. President Vladimir Putin was addressing a meeting mark the occasion at the time of the shooting. There was no immediate official information on the shooting.