'Who poisoned Navalny?', nervous EU asks Russia

"Those responsible must be identified and brought to justice," German chancellor Angela Merkel said.

"Russian people, as well as the international community, are demanding the facts," EU foreign relations chief Josep Borrell added.

Navalny was poisoned with a nerve agent that inhibits breathing, Charité had confirmed earlier in the day, prompting the alarm.

A German NGO had flown him out of Russia for treatment after he collapsed last weekend, but German authorities feared for his safety even in the heart of Europe.

"Because there is a certain probability of a poison attack, protection is necessary," Merkel's spokesman, Steffen Seibert, told press on Monday.

Germans shared photos of police outside Navalny's clinic on social media.

"Does Putin want to have him [Navalny] killed in Berlin too?", German tabloid newspaper Bild also asked in an online debate, referring to Russian president Vladimir Putin.

The security fears came after Germany recently accused Russia of assassinating an exiled opponent in a Berlin park last summer.

Austria also arrested two Russians for a political murder in Vienna in July.

And the UK has accused the Kremlin of poisoning a former spy in Britain in 2018, in a long list of lethal operations on both European and Russian domestic territory.

"It's just a touch suspicious that someone [Navalny] vehemently opposed to the Russian state should fall ill in this way," Hamish de Bretton-Gordon, a UK chemical and biological weapons expert, told British newspaper The Guardian on Monday.

For its part, Russia tried to cast doubt on Charité's findings.

The Kremlin kept quiet.

But Navalny had tested negative for the nerve agent, a so called "cholinesterase inhibitor", in a Russian hospital prior to leaving the country, Russian health officials said.

And Germany might have poisoned him on the flight to Berlin in a false-flag operation, Igor Molchanov, a Russian health ministry specialist, added.

For some security experts, the fact Russia keeps getting caught red-handed in assassination attempts is a sign of its intelligence cackhandedness.

But for others, it is a deliberate tactic, designed to intimidate Kremlin foes, Western governments, and the wider general public.

And Russia trolled the airwaves, also on Monday, when its security services bragged in a Russian tabloid, the Moskovsky Komsomolets, that they had been following Navalny before he suddenly fell unconscious.

The surveillance did "not surprise" Kira Yarmysh, a Navalny spokesman. "What's surprising, however, is that [Russian services] did not shy away from describing it," Yarmysh said.

The assassination attempt coincided with huge pro-democracy protests in Putin's neighbour, Belarus, prompting speculation that Navalny might have been targeted to stymie activism in Russia.

The international scale of events will come into view on Tuesday, when the US deputy secretary of state, Stephen Biegun, holds talks on Belarus in Moscow.

Targeted US sanctions on Russia over Navalny could also be on the agenda.

"If Navalny had been poisoned, this is very significant for the United States," Biegun said on the eve of his trip.

State sadism?

But whatever the geopolitics of the poisoning, it is the 44-year old activist who is paying a personal cost.

"It looks funny, but it hurts like hell," Navalny said, in 2017, after an attacker sprayed green dye in his face.

"It's scary to not be able to breathe," Vladimir Kara-Murza, a Kremlin critic who was also poisoned, wrote recently in US newspaper The Washington Times, speaking of his own experience.

"That was the first thing I felt, both times the poisoning symptoms began to set in ... My chest was expanding, all the normal physical motions were there, but it felt as if I was suffocating. The other symptoms - racing heartbeat, excessive perspiration, violent vomiting, loss of consciousness - came later," Kara-Murza said.

"Apart from its sadism ... this method gives the authorities plausible deniability," he said.

"Navalny will survive the poison attack, but he will be incapacitated for months," Jaka Bizilj, the head of the German NGO, Cinema for Peace, which extracted Navalny from Russia also said on Monday.