MOSCOW — U.S. tech giants were thrust into the middle of the battle for Russian Internet freedom on Thursday as Instagram apparently bowed to a court order to block access to posts that embarrassed an oligarch and a top government official.

Russia’s telecommunications regulator also said it had ordered service providers to block the website of opposition leader Alexei Navalny, whose team dug up Instagram posts that showed metals magnate Oleg Deripaska and Deputy Prime Minister Sergei Prikhodko socializing on a yacht in Norway. 

Navalny had posted a YouTube video showing the Instagram posts and presenting evidence that women aboard Deripaska’s yacht worked for an escort service, and it went viral in Russia last week. Deripaska successfully sued for the removal of the posts and Navalny’s video, claiming they violated his right to privacy, and this week the government started implementing the court order. 

Even as authorities detained organizers and raided the office of opposition leader Alexei Navalny, thousands called for a boycott of the upcoming election. (The Washington Post)

On Thursday, telecom regulator Roskomnadzor said that it had ordered Navalny’s website blocked and that it was satisfied that the Instagram posts that Deripaska sought to remove were no longer available. Google, however, had not yet complied with the demand to take down Navalny’s video on its YouTube platform, the agency said.

“Roskomnadzor is hoping for a positive decision by Google,” the agency said in a statement. 

Google did not immediately respond to a request for comment. Facebook, which owns Instagram, issued a statement saying that governments may ask the company to restrict access to content they say violates their laws. 

“We review such requests carefully in light of local laws and where appropriate, we make it unavailable in the relevant country or territory,” a Facebook spokeswoman said. 

What you need to know about Paul Manafort's ties to Russia. (Thomas Johnson/The Washington Post)

Navalny criticized Instagram on his Twitter account, which remained accessible. 

“Instagram decided to comply with Russian illegal censorship requests and deleted some content about oligarch Deripaska,” Navalny said on Twitter. “Shame on you, Instagram!”

The fight touched off by Navalny’s video, which has been viewed more than 5 million times, represents the latest escalation between the Russian government and opposition activists over freedom of speech online. While the state under President Vladimir Putin controls the top television networks and has cracked down on independent news media, many opposition websites and critical social network accounts remain freely accessible. 

Navalny, who rose to prominence as an anti-corruption activist and now is calling on supporters to boycott the March 18 presidential election, has used the Web to gain a nationwide following despite being shut out of the state-controlled media. His fast-paced YouTube videos presenting evidence of government corruption have helped propel anti-Putin protests by thousands of people across Russia on several occasions in the past year. 

Analysts say that fear of a public and international backlash, as well as a desire to maintain a veneer of openness at home, has so far discouraged the Kremlin from trying to shut down Navalny’s communication channels. 

The state response to Navalny’s latest video suggests a new, tougher approach. While his site has been blocked several times in the past, his most-watched video so far — an investigation last year into the hidden wealth of Russian Prime Minister Dmitry Medvedev — remains accessible on YouTube. 

In last week’s video, Navalny shows Instagram posts he says were unearthed by his team that were put up by a woman who said she worked for an escort agency and claimed to have been romantically involved with Deripaska, one of Russia’s richest men. 

The Instagram posts appear to show the aluminum tycoon relaxing on a yacht in Norway in 2016 together with Prikhodko. Navalny said the posts and other evidence he collected showed Deripaska was bribing Prikhodko with the yacht trip and women working for an escort service. 

Prikhodko responded by calling Navalny a “political loser” whose video combined “the possible and the impossible.” Deripaska issued a statement saying Navalny’s “allegations have nothing to do with reality” and sued the woman who made the Instagram posts. 

“Mr. Deripaska’s claim is to protect his right to privacy, and has nothing to do with any political struggle between Mr. Navalny and his political opponents,” his company Basic Element said in a statement Thursday.

Deripaska filed his lawsuit in Ust-Labinsk, the town in southwest Russian where he grew up. The court, in a proceeding closed to the news media, ordered the woman’s Instagram posts to be removed. 

“The information whose accessibility the Ust-Labinsk regional court demanded be limited has been removed from the pages of the Instagram social network,” Roskomnadzor said in its statement Thursday.