Chief of Russia's military intelligence agency dies

The head of the Russian military intelligence agency linked to a series of notorious operations abroad has died after a long illness, the defence ministry said on Thursday.

Igor Korobov, 62, had headed the military's Main Intelligence Directorate (GRU) since 2016 and was the target of US sanctions.

He died on Wednesday from a "long and serious illness," the ministry said in a statement carried by Russian news agencies.

"The dear memory of this great man, a faithful Russian son and a patriot of the Motherland... will remain forever in our hearts," the ministry said.

His successor has yet to be announced.

The West has accused the powerful agency of a number of attacks on foreign soil including the poisoning of former Russian spy Sergei Skripal and his daughter Yulia with a nerve agent in Britain last March.

Washington has said the GRU was directly involved in interfering in the 2016 US election through "cyber-enabled activities" and the Treasury Department included Korobov on a sanctions list.

Korobov did not participate in a gala marking the centenary of the service in early November when Russian President Vladimir Putin heaped praise on the GRU. Korobov's first deputy Igor Kostyukov reportedly presided over the ceremony.

Korobov, who joined military intelligence in 1985, was made a Hero of Russia for his service.

His predecessor, Igor Sergun, died unexpectedly in early January 2016. The GRU is one of Moscow's three spy agencies, along with the SVR foreign intelligence agency and the FSB security service.

It has an extensive spy network abroad and its highly trained "spetsnaz" special forces have fought in various conflicts, including in Afghanistan and Chechnya.

The agency's structure, staff number and finances are a state secret. Its emblem is a black bat flying above a globe.