MOSCOW (AFP) - Russia said on Tuesday (Dec 22) that it was hitting EU officials with sanctions for their response to the poisoning of opposition figure Alexei Navalny, who the Kremlin said was suffering from "delusions of persecution".

The foreign ministry in Moscow summoned several senior EU diplomats before announcing the new travel bans.

In response to "confrontational" sanctions imposed by the bloc in October, Russia "decided to expand the list of representatives of EU member states and institutions who will be denied entry to Russia".

The announcement on Tuesday came a day after Mr Navalny, 44, said in a report he had impersonated an official in the Kremlin's Security Council and extracted an admission of guilt from a toxins expert with the FSB security service.

In a video of the conversation published by Mr Navalny, the alleged FSB agent is heard saying agents placed poison in Navalny's underwear this summer.

The anti-corruption campaigner was flown for treatment to Germany where labs concluded he was poisoned with Novichok, a Soviet-designed nerve agent.

Mr Navalny's video of his conversation with the man named Konstantin Kudryavtsev racked up more than 12 million views in less than 24 hours and social media were abuzz with memes about Mr Navalny's underpants.

The Kremlin on Tuesday described Mr Navalny as a "sick" man who was suffering from "delusions of persecution".

President Vladimir Putin's spokesman, Mr Dmitry Peskov, denied that Mr Navalny's claims could discredit the FSB, adding that the opposition politician also exhibited "traits of megalomania".

"They say he compares himself to Jesus," Mr Peskov added.

'Political Chernobyl'

Observers said it was hard to predict the fallout from Mr Navalny's revelations.

"This is a political Chernobyl," said prominent commentator Yulia Latynina, referring to the 1986 nuclear disaster in Soviet Ukraine.

"After this, the system cannot exist in its current form," she wrote in the opposition newspaper Novaya Gazeta.

The authorities hit back against Mr Navalny's supporters. His top ally, Ms Lyubov Sobol, spent hours at a police station and was questioned overnight before being released.

Mr Ivan Zhdanov, the head of Mr Navalny's Anti-Corruption Fund, told AFP that they planned to launch a formal complaint with the FSB on Tuesday.

The FSB described the phone call as "fake" and said it would not have been possible without "the support of foreign intelligence services".

Last week, Mr Putin rejected reports that the FSB had poisoned Mr Navalny, saying that if the security services had wanted to poison the opposition politician, "they would have taken it to the end".

Mr Putin, himself a former KGB officer, over the weekend hailed Russia's "courageous" spies and thanked them for protecting the country from "external and internal threats".

'Intelligence 101'

But some analysts said Mr Navalny's revelations raised new questions about the professionalism of Russia's security services.

"Intelligence 101: Always insist on calling back, never simply take a call from someone you do not recognise," said Mr Wolfgang Ischinger, chairman of the Munich Security Conference.

This, he quipped, was "apparently not being taught in FSB graduate school".

The counter sanctions were announced after Moscow summoned senior diplomats from Germany, France and Sweden, the three countries where labs have said Mr Navalny was poisoned with Novichok.

The findings resulted in EU sanctions against several Russian officials in October, including the head of the FSB.

Navalny fell violently ill during a flight from Siberia to Moscow in August and was hospitalised in the city of Omsk before being transported to Berlin by medical aircraft.

The person Mr Navalny said was the FSB agent was heard in the video saying the security services had not expected the pilot to make an emergency landing in Omsk.

He said that if the flight had been allowed to continue, Mr Navalny would not have survived.

Ms Sobol on Monday went to the Moscow apartment where Kudryavtsev is believed to live. She was detained and spent more than six hours at a police station.

Last week, a joint media report led by the Bellingcat investigative website revealed what it said were the names and photos of chemical weapons experts from the FSB that had tailed Mr Navalny for years.