At a news conference after meeting Russian Foreign Minister Sergey Lavrov, Borrell said he had conveyed the EU's deep concern and reiterated the bloc's appeal for Navalny's release from prison, as well as the launch of an investigation into his poisoning, which Navalny and foreign governments blamed on the Kremlin. 

"While we fully respect Russian sovereignty ... the European Union considers issues related to the rule of law, human rights, civil society and political freedom central to our common future." 

Questioned by a reporter about whether the EU would be taking any new action against Russia on the Navalny case, Borrell said a "full and transparent investigation" could help clarify what happened to the opposition figure. But he said no EU member state had proposed extra sanctions on Russia for now.  

Last month, EU foreign ministers failed to agree on further sanctions against Russia over the detention of Navalny and his supporters. The Kremlin dismissed Western calls for Navalny's release Friday. 

"Any hints of an ultimatum are absolutely unacceptable to us, we have already said that we won't listen to such patronizing statements," said Kremlin spokesperson Dmitriy Peskov. 

On Tuesday, Navalny was jailed for nearly three years in what his supporters say is a spurious fraud case. 

Borrell's pre-planned visit comes as more details are emerging of the treatment by police of detained anti-Kremlin protesters. Rights campaigners say protesters are being handled with increasing brutality and detainees are being crammed into unsanitary, squalid and crowded cells with no regard for the risk of coronavirus transmission. 

Activists also complained of being beaten and kicked while detained, and one activist arrested at a Moscow protest said she was forced to disclose her cellphone password by being suffocated.  

"A police officer put a plastic bag over my head and started to hit me," Alyona Kitaeva told Dozhd, an online Russian news channel. She says police threatened to shock her with a stun gun. "In Putin's Russia, first they torture you, and then they imprison you," Navalny's anti-corruption group said. 

On Thursday, Kremlin spokesman Peskov admitted detention centers were struggling to process and handle the large number of protesters arrested this week. "There are more arrested than the detention centers can handle, and there are more detainees than can be processed in a short time. Therefore, unfortunately, such consequences arise," he said. 

But he dismissed allegations of repression, which he dubbed an "emotional assessment," saying, "there are police measures against violators of the law." He added, "You forget that during the actions there were direct and multiple attacks on employees [police]. The answer was tough, but in line with the law." 

Independent rights monitors estimate more than 10,000 people, including 80 journalists, have been detained nationwide during protests last week and this week. Protesters are demanding Navalny's release from prison. 

Videos shot by a variety of broadcasting companies recorded riot police bludgeoning protesters with truncheons and shocking them with stun guns. 

Rights monitors with Analogia Protesta, a Telegram messaging channel, estimate 130 protesters were injured in Moscow, suffering from head injuries, broken noses and cracked ribs. Officials say they investigate allegations of police brutality, but authorities are yet to charge a police officer who kicked a 54-year-old woman during a protest in St. Petersburg last month and who had to be rushed to a hospital for her injuries. 

International rights campaigners urged Borrell to demand the Kremlin free all those arrested. His visit is the first conducted by a senior EU envoy since 2017. 

"Borrell should also make it clear that he and the EU view the attacks on Navalny and the vicious crackdown on public protests as the tip of the iceberg of Russia's deliberate and persistent efforts to silence democratic voices with increasingly restrictive laws and politically motivated prosecutions," said Philippe Dam, advocacy director for the Europe and Central Asia Division of Human Rights Watch. 

"Borrell will also be scrutinized by the thousands of Russian citizens who are faced with new waves of repression because they stood up against corruption and injustice," he said. 

Amnesty International accused Russian authorities of shredding "any remaining veneer of justice and respect for human rights" in its handling of the protests. Natalya Zviagina, Amnesty's Moscow director, said the Kremlin seems "intent on locking up anyone who dares to speak out against their abuses and repression of human rights." 

She added, "This latest crackdown stands out for its viciousness and sheer scale. There are now more detainees in Russia than there are prison cells, which means people who have done nothing more than attend peaceful demonstrations are being held incommunicado on overcrowded police buses with inadequate sanitation, and in the face of the risks posed by the COVID-19 pandemic." 

Rights campaigners say there are also consistent and credible reports of detainees being kept for prolonged periods inside police buses before being transferred to detention centers, with limited or no access to food, water or toilets. 

Photographs tweeted Thursday from the account of detained journalist Sergei Smirnov, editor of the independent news website, Mediazona, highlighted the filthy and cramped conditions in Sakharovo, a detention facility 70 kilometers from downtown Moscow normally used to process illegal migrants before deportation. The photos show 28 detainees packed into a cell designed for eight people. 

Borrell's trip was planned before pro-Navalny demonstrations erupted across Russia. Some EU member states argued for a cancellation of the visit, fearing it was unfortunately timed and would expose EU impotence. The Baltic states, alongside Poland and Romania, called instead for a new set of sanctions to be imposed on Russia. Their fear was that a dialogue with the Kremlin over the Navalny case at this stage would be a hopeless endeavor and would undermine EU credibility. 

Borrell's announcement Friday that he hoped the EU's medicines regulator will soon authorize the use of Russia's Sputnik V coronavirus vaccine prompted the surprise of Central European diplomats. "This is what we feared beforehand — that our condemnation of the Kremlin's tactics to quell internal dissent would be diluted," said a Baltic diplomat, who asked not to be named. 

VOA