Russia on Tuesday slapped tit-for-tat sanctions on EU officials over their response to the poisoning of Alexei Navalny, saying the opposition leader had a persecution complex and "compares himself to Jesus."
Moscow summoned several senior EU diplomats before announcing the new travel bans in response to what it said were "confrontational" sanctions imposed by the bloc in October.
The foreign ministry said Moscow "decided to expand the list of representatives of EU member states and institutions who will be denied entry to Russia."
The announcement came a day after Navalny, 44, said 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 Navalny, the alleged FSB agent says agents placed poison in Navalny's underwear in August.
The anti-corruption campaigner was flown for treatment to Germany where labs concluded he was poisoned with Novichok, a Soviet-designed nerve agent.
His video racked up more than 13 million views in 24 hours and social media was abuzz with memes featuring Navalny's underpants.
President Vladimir Putin's spokesman on Tuesday described Navalny as a "sick" man who was suffering from "delusions of persecution" and also exhibited "traits of megalomania."
"They say he compares himself to Jesus," said Dmitry Peskov, adding the opposition leader had a "Freudian" fixation on his own crotch.
Police later on Tuesday detained prominent filmmaker Vitaly Mansky outside the FSB headquarters in central Moscow where he staged a one-man rally holding a pair of blue underpants.
Authorities also hit back against Navalny's supporters. His top ally Lyubov Sobol was detained late Monday and spent hours at a police station before being released.
- 'Political Chernobyl' -
Observers said it was difficult to estimate how far-reaching the fallout of Navalny's claims would be.
"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.
Ivan Zhdanov, the head of Navalny's Anti-Corruption Fund, told AFP that Navalny's allies planned to launch a formal complaint with the FSB on Tuesday.
The FSB has described the phone call as "fake" and said it would not have been possible without the support of foreign intelligence services.
Last week Putin rejected reports the FSB had poisoned Navalny, saying that if the security services had wanted to poison the opposition politician, "they would have taken it to the end."
Putin, himself a former KGB officer, hailed at the weekend Russia's "courageous" spies and thanked them for protecting the country from "external and internal threats."
- 'Unjustified sanctions' -
Some analysts said Navalny's claims raised fresh 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 Wolfgang Ischinger, chairman of the Munich Security Conference
This, he quipped, was "apparently not being taught in FSB graduate school".
Tuesday's counter sanctions were announced after Moscow summoned diplomats from Germany, France and Sweden, the three countries where labs have said Navalny was poisoned with Novichok.
The findings resulted in EU sanctions against several Russian officials in October, including the head of the FSB.
A German foreign ministry source said the counter measures were "unjustified."
"We continue to call on Russia to clarify the use of a chemical weapon on Russian territory against a Russian citizen," the source told AFP.
"Russia has shown no willingness to do so."
Navalny collapsed during a flight from Siberia to Moscow in August and was hospitalised in Omsk before being transported to Berlin.
The person Navalny identified as an 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, Navalny would not have survived.