A Russian soldier on Monday opened fire at a military airfield and killed three people, officials said, adding the gunman has barricaded himself on the territory of a military unit.

The shooting took place at the Baltimore military airfield near the city of Voronezh, TASS News Agency reported.

"A military serviceman opened fire with a handgun, which he took from an officer. Three people have been killed. Now he (the attacker) has barricaded himself on the territory of the (military) unit," a source in the regional emergency services said.

A fourth soldier has sustained gunshot wounds, the BBC reported.

The motive of the shooting remains unknown.

The airfield, which is part of the Air Force Academy, has been under repair for more than seven years.

In December 2019, plans were announced to complete it by September or October 2020, said the TASS news report.

Its runway is designed for all types of modern aircraft, both military and civilian..