Jailed Kremlin critic Alexei Navalny said Tuesday that Russians must continue to protest against the war in Ukraine.

More than 13,500 citizens across Russia have been detained at demonstrations since President Vladimir Putin ordered the invasion of Ukraine on February 24.

And Navalny tweeted that "whether Russians actually support the hideous war that Putin has waged against Ukraine will largely define Russia's place in the history of the 21st century."

'Putin's bloody venture' must not be supported

In a 14-part thread posted on Twitter, Navalny said: "It's one thing if Putin killed Ukrainian civilians and destroyed life-critical infrastructure with full approval from the Russian citizens. However, it's a whole different story if Putin's bloody venture is not supported by the society."

Navalny wrote that public opinion is shifting against Putin, citing a survey carried out by aides.

"We can observe rapid shifts in the evaluation of Russia's role in the war. The share of respondents who view Russia as the aggressor doubled, while the share of those considering Russia a "peace-maker" halved," he tweeted.

"The nature of these changes is plain and unambiguous: people rapidly begin to realize who is responsible for initiating the conflict, as well as the war's true objectives and possible outcomes."

Navalny: Kremlin worried

"Undoubtedly, the Kremlin can see these dynamics as well," he continued. "Hence the nervousness, the desperate attempts to end the war campaign as soon as possible."

Navalny is currently serving a two-and-a-half-year jail term on fraud charges that his allies say are politically motivated while Navalny says the Kremlin is keeping him in prison to stifle political resistance in Russia.

In new charges brought against the opposition figure last month, Russian authorities allege Navalny stole $4.7 million (€4.1 million) worth of donations to his political organization. He is also accused of insulting a judge.

If convicted in the new case, Navalny could see his time in prison extended by more than 10 years.

'Anti-war protests should not be halted under any circumstances'

But it didn't stop him from attempting to galvanize the public on Tuesday, as Putin's conflict edged towards its third week.

"The anti-war momentum will keep growing across the society, so the anti-war protests should not be halted under any circumstances," he tweeted. "People are generally willing to change their stance, but only if we engage them in the dialogue and provide them with true information about the war."

Last week, President Putin signed legislation imposing jail terms for publishing "fake news" about Russia's invasion of Ukraine. The move led several news organizations to reevaluate their operations in Moscow. Other international news agencies, including DW, have been blocked inside Russia along with the social media networks Facebook and Twitter. The move has serious implications for Russians' ability to access independent sources of information.

Edited by: Rob Turner