The Russian spy agency has said telephones belonging to foreign diplomats based in Russia and the former Soviet Union, including those from Israel, Syria, China and Nato members, had been targeted.

A number of US citizens have been detained on criminal charges in Russia in recent years, with some ultimately freed in exchange for Russians detained in the US.

Putin instructed the services to increase control of the society and maximise their 'use of the operational, technical and personnel potential' to prevent risks coming from abroad and internal traitors.

The FSB says the explosion was organised by Ukrainian military intelligence and its director, Kyrylo Budanov.

The FSB says the consul was declared persona non grata after he was caught 'red-handed' receiving secret information on the effects of Western sanctions on the economic situation in Russia's far east.

After Moscow's offensive in Ukraine, the country has strengthened its legislative arsenal, allowing for heavy fines or prison sentences for anyone found guilty of 'discrediting' or publishing 'false information' about its operation.

In a post in Russian on its official website, the intelligence arm of the Ukrainian defence ministry listed people it said were FSB employees registered at the agency's headquarters in Moscow.