MOSCOW, July 13. /TASS/. Russia is looking into the possibility of building two extra Borei-class and two extra Yasen-class submarines, a source in Russia’s defense industry has told TASS.

"In addition to the 10 Borei/Borei-A-class missile carriers and nine Yasen/Yasen-M attack submarines, at least two extra submarines may be built within each of those two families," the source said.

In his words, the keel laying for some of them may take place later this year at the Sevmash shipyard.

TASS was unable to officially confirm this information at the time of the publication.

Earlier, an unnamed source told TASS that two Borei-A nuclear-powered ballistic missile submarines (NATO reporting name: Dolgorukiy-class) will be laid down by the Sevmash Shipyard (part of the United Shipbuilding Corporation) in 2023.

By now, Sevmash has produced five Borei-class submarines for the Russian Navy.

Besides, Russia has three Yasen-class underwater cruisers in service, while six more are at various stages of completion.