One officer of the Federal Penitentiary Service (FSIN) was killed and three others were injured when a convict under escort attacked staff inside a prison transport train car in Kabardino-Balkaria, Russia’s North Caucasus.

Axar.az reports, citing TASS, that according to the FSIN press service, the attacker has been liquidated.

"During rail transit near Murtazovo station, a convict being escorted to the restroom launched a solo attack on a convoy officer and seized his service weapon. As a result of the attack, one officer died and three others were wounded," the statement said.

The attacker was killed by the escort guards during the incident. There were no civilian casualties.