A second FSB officer has died after an attack on the Russian security service's headquarters in Moscow on Thursday.
He was taken to hospital yesterday in a critical condition where he died, authorities said.
It came as the Investigative Committee, the nation's top state investigative agency, identified the attacker as 39-year-old Yevgeny Manyurov, who lived in Moscow's suburbs. He was killed by police during the attack.
Five others were wounded in the incident, which happened a short distance from where Russian president Vladimir Putin was addressing security personnel on Thursday evening.
The Federal Security Service, or FSB, said the assailant was acting alone and didn't enter its building.
On the scene in Moscow, Euronews correspondent Galina Polonskaya said: "We know that the FSB said that it has neutralised this person.
"It was near the headquarters of the FSB, sometime after the end of the annual press conference of the Russian president."
Polonskaya said that the attacker was using a Kalashnikov assault rifle.
The mayor of Moscow, Sergueï Sobianine, has said that the injured were receiving "all necessary care" in hospital.
Putin's spokesman, Dmitry Peskov, said the president had been informed of the shooting that came shortly after the Russian leader's annual news conference.
Putin was making a speech at a Kremlin concert for FSB and other Russian security personnel around the time of the attack.
In a speech marking the date the Soviet secret police was founded, Putin hailed its officers for their efforts in combating terrorism and organized crime.
"Russia is not really keen to even acknowledge that there are terrorist attacks in Russia, particularly in the capital," Polonskaya said.
December 19, known as Security Services Day, is a national holiday in Russia. Earlier, Putin gave a four-hour press conference in the Russian capital.