There have been social media messages calling for peace, an image of a murdered Russian opposition figure, a newspaper editorial demanding President Vladimir Putin "stop this war."

As Russian forces pound Ukraine's cities, the sentiments might not be surprising. Their source is — they come from rich Russians, including billionaires close to the Kremlin.

Russia's war on Ukraine has sent shockwaves through the global community of wealthy Russians, who face sanctions that threaten their London mansions, Mediterranean yachts and children's places at elite European private schools.

Some have begun, albeit tentatively, to speak out — though it may be too little to end the war, or to protect their Western fortunes.

"It's very cautious steps, but nevertheless you can see they are already thinking of the future and trying to save whatever they can," said Elisabeth Schimpfössl, author of the book "Rich Russians."

President Joe Biden told oligarchs in Tuesday's State of the Union address that "we are joining with our European allies to find and seize your yachts, your luxury apartments, your private jets. We are coming for your ill-begotten gains."

As violence escalated, and as the U.S., Britain and other countries announced plans to seize assets and limit their ability to stow money in Western banks, some wealthy Russians earlier this week began voicing opposition to war.

On Monday, London's Evening Standard newspaper published a front-page statement by its Russia-born owner, Evgeny Lebedev. "President Putin, please stop this war," ran the headline, beside a photo of a young Ukrainian girl killed by shelling.

"As a Russian citizen I plead with you to stop Russians killing their Ukrainian brothers and sisters. As a British citizen I ask you to save Europe from war," wrote Lebedev, who is the son of oligarch and former KGB agent Alexander Lebedev.

Lebedev is close to leading British politicians and was appointed to Parliament's House of Lords by Prime Minister Boris Johnson, but he had previously refrained from criticizing Putin.

Three other Russian business tycoons — metals magnate Oleg Deripaska, Alfa Bank founder Mikhail Fridman and banker Oleg Tinkov — also urged an end to the war.

Deripaska, who founded the Rusal aluminum company and is considered an ally of Putin, wrote on the Telegram messaging service that "peace is very important" and talks to end the war should begin "as soon as possible."

Tinkov, founder of Tinkoff Bank, on Monday posted on Instagram: "Innocent people are dying in Ukraine now, every day, this is unthinkable and unacceptable."

Neither mentioned Putin directly. Nor did London-based billionaire banker Fridman, who this week was placed on a European Union sanctions list. Fridman, who was born in the Ukrainian city of Lviv, called the war a "tragedy" that "should be stopped as soon as possible." But he grew visibly uncomfortable when asked to criticize Putin.

"Hundreds of thousands of people are working for us in Russia. And you know, I don't want to make any comments which potentially could increase their risk," Fridman told reporters on Tuesday.

Fridman also railed against his sanctioning by the EU, which called him an "enabler of Putin's inner circle."

"Imposing sanctions against us here just creates enormous pressure for us personally," he said. "But we do not have any impact (on) political decisions at all."

The oligarchs' power to change the course of the war is probably limited. Western officials believe Putin's inner circle is extremely small. Oligarchs who have fallen out with Putin have often ended up exiled, in prison or dead.

This week Anatoly Chubais, a veteran oligarch who oversaw Russia's 1990s privatizations, posted a photo of Boris Nemtsov, a leading Russian opposition figure who was shot dead near the Kremlin in 2015. Even without a caption, it was seen as a powerful statement from a Moscow insider.

Schimpfössl, a senior lecturer at England's Aston University, said the war and the responding sanctions had made it harder for Russia's elite to live a "double life" — keeping in the Kremlin's good books while living a life of luxury in the West.

"They all have blood on their hands. But nevertheless a lot of their life also is happening here," in the West, she said. "And having that taken away from them is extremely painful for them."

"I think it will be much more difficult for them to just be apolitical," she said, adding that those who are speaking out were seeking to strike a balance: "trying not to make Putin too angry while thinking into the future" beyond the Russian president's time in power.

Chelsea Football Club owner Roman Abramovich — one of the highest-profile oligarchs who is not yet on a sanctions list —- has even offered to help broker peace.

A spokesman said Abramovich "was contacted by the Ukrainian side for support in achieving a peaceful resolution, and that he has been trying to help ever since." It was unclear what help he could provide, and some suggested the move was an attempt to keep his name off the U.K. sanctions list.

Abramovich, a metals magnate and Putin ally whose net worth is estimated at more than $13 billion, looks increasingly likely to face British sanctions. He said Wednesday he was seeking to sell Chelsea, one of the world's top soccer teams, "in the best interests of the club." He'd earlier said he planned to hand stewardship of the team to its charitable foundation in an attempt to keep it out of sanctions range.

Abramovich is one of many wealthy Russians with strong U.K. ties. Only a handful have been sanctioned by British authorities so far, even as the U.K. has joined the U.S. and European nations in cutting off Russian banks and closing skies to the country's planes.

Critics of Putin say Western countries have long turned a blind eye to ill-gotten Russian money. The U.K., in particular, has welcomed wealthy Russians as they snapped up luxury properties and British businesses, sent their children to expensive private schools and hired fleets of London lawyers and public relations experts to keep their reputations clean.

The anti-corruption group Transparency International says Russians linked to the Kremlin or accused of corruption own 1.5 billion pounds' ($2 billion) worth of London property.

The attack on Ukraine has prompted an overnight change. Johnson said the U.K. would "tear back the facade that those supporting Putin's campaign of destruction have been hiding behind for so long."

Even neutral, discreet financial haven Switzerland has joined the EU in imposing sanctions.

U.K.-based American financier and anti-corruption campaigner Bill Browder, who has campaigned for sanctions on Russia for years, says Western governments have finally woken up. But he said Putin will only be deterred if the West goes after his personal fortune — much of it elusive and believed to be held by key allies.

"The key is that there has to be a cost to him. And if there is no cost to him and him personally, he will carry on," Browder said.

One who knows the cost of crossing Putin doubted many others would be willing to pay the price of strong opposition to the Russian leader — or that Putin would listen.

"I think that many Russian oligarchs, including Roman Abramovich, are now trying to be nice to both sides," said Mikhail Khodorkovsky, a former oil baron who spent a decade in prison in Russia after falling out with Putin.

"Putin will conduct negotiations seriously only when he understands that he is stuck in Ukraine," he told the BBC. "In reality, Putin will be inclined to have negotiations only if Ukraine's defending forces and its society force him to do so."