Navalny supporters protest his arrest, in Moscow
Law enforcement officers detain a man during a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Jan. 23, 2021.

MOSCOW - Foreign Ministers of the European Union are meeting in Brussels Monday to debate the response of the 27-nation bloc to Russia's arrest of opposition leader and Kremlin critic Alexei Navalny and the police crackdown on pro-Navalny demonstrators, as pressure grows to impose sanctions on the Kremlin.

Arriving for the meeting, EU foreign policy chief Josep Borrell said that the most recent "wave of detention is something that worries us a lot, as well as the detention of Mr. Navalny."

German Foreign Minister Heiko Maas said that "everyone in Russia has the right to express their opinion and to demonstrate" under the Russian constitution. "The principles of the rule of law must apply there, too," Maas added, "Russia has always committed itself to that."

Speaking to France-Inter radio Sunday, French Foreign Minister Jean-Yves Le Drian discussed what he called Russia's "authoritarian drift," saying that "all light must be shed" on Navalny's poisoning as an "assassination attempt."

EU leaders have called on Russia to immediately release Navalny and all pro-Navalny protesters in detention.

The United States strongly condemned the arrests and use of "harsh tactics against protesters and journalists this weekend in cities throughout Russia," State Department spokesperson Ned Price said in a statement Sunday. 

WATCH: In Russia, Hundreds Behind Bars Following Pro-Navalny Protests

Suppression of Russians' rights to peaceful assembly and freedom of expression, Navalny's arrest, and the crackdown on protests "are troubling indications of further restrictions on civil society and fundamental freedoms," the statement added.  

The U.S. is calling on Russian authorities "to release all those detained for exercising their universal rights and for the immediate and unconditional release" of Navalny, Price said, adding that U.S. is urging Russia "to fully cooperate with the international community's investigation into the poisoning" of the Kremlin critic, and "credibly explain the use of a chemical weapon on its soil." 

Russia's Foreign Ministry issued a statement countering that the U.S. efforts to "incite radical elements" on social media would have negative effects on U.S.-Russian relations -- adding American diplomats in Moscow would be summoned for "a serious conversation."  

Hundreds of people remained behind bars in Russia Sunday, a day after they were arrested for participating in nationwide street protests demanding the release of Navalny.

People gather in Pushkin Square during a protest against the jailing of opposition leader Alexei Navalny in Moscow, Jan. 23, 2021.

Protests across Russia

Tens of thousands of supporters of jailed opposition politician Alexei Navalny thronged the streets of Russia Saturday, defying warnings from authorities that those attending faced police arrest and additional health risks because of the coronavirus. 

The protests were called by Navalny after the opposition leader was jailed upon his return to Russia last weekend from Germany, where he'd been recovering from a poisoning attack that nearly took his life last August.

Independent monitoring group OVD-Info reported about 3,200 arrests as of Saturday night, including Navalny's wife, Yulia, and his aide, politician Lyubov Sobol. Several dozen journalists were also detained. 

Yulia Navalnaya confirmed her arrest in Moscow in an Instagram post created from inside a police van, apologizing for the look of her posting. "Sorry for poor quality. Very bad light in a paddy wagon," she wrote Saturday. 

Thousands of Navalny's supporters were in the streets of more than 60 Russian cities Saturday to demand the Kremlin critic's immediate release, defying the measures taken by police to break up the protests, which they have declared illegal. 

Police detain a man during a protest against the jailing of opposition leader Alexei Navalny in Khabarovsk, 6,100 kilometers (3…
Pro-Navalny Rallies in More Than 60 Russian Cities
Police are arresting supporters of the Kremlin critic who are demanding his immediate release

In Moscow, thousands of masked protesters gathered in the city's central Pushkin Square with shouts of "Let him Go!" and "Alexei! Alexei!"

Demonstrators also held signs that read "Freedom for Navalny" and "I'm not Afraid."

"If they arrest me, well OK, I'll miss a day or two of work," said Dmitry, 55, in an interview with VOA.

"I'm here thinking of my children and their futures. Because I absolutely don't like what's happening now in our country these days," he added.

Many of the demonstrators were in their 20s and some even in their teens — a fact government officials have seized on, accusing Navalny of luring minors into harm's way.

"I've known only one president my whole life and I'm tired of him," said Ksenia, 24, in explaining why she'd come. 

"I didn't come out for Navalny. I came out for me," said Daria, 17, a high school senior. "I want my country to change."   

Crowds also overflowed onto the surrounding side streets and along the city's main Tverskaya thoroughfare.

Drivers blared their horns in a near constant drone of support for the demonstrators.

Most out on the streets appeared peaceful.

Yet, toward evening, a group of protesters were seen pelting OMON riot police, a system of special police units, and a car belonging to the Federal Security Service, or FSB, with snowballs. The driver reportedly was injured after being hit in the eye.

Nearby, a smoke grenade had been lobbed into the area, apparently from a demonstrator, filling the air with an acrid smell.

Throughout the day, various witness videos posted to social media showed riot police roughly detaining protesters, in some cases beating demonstrators with batons. There were reports of multiple injuries.     

Dozens of Navalny supporters were arrested during a standoff outside Moscow's Matrosskaya Tishina prison where Navalny is currently being held.      

In one graphic scene in St. Petersburg, an OMON riot trooper was filmed kicking a woman in the stomach — sending her sprawling after she asked about the arrest of another demonstrator.  

   Russia's state RIA-Novosti news service reported 39 policemen had received minor injuries during the day.

Navalny's national reach

The turnout provided further evidence that Navalny has built a national presence across the country, despite a near total ban on coverage in state media.

Indeed, Navalny's popularity has grown largely based on a savvy social media campaign and online video investigations that claim to uncover corruption among Kremlin elite.

Even this week, with Navalny in prison, his team released a lengthy video online that claims to have discovered a lavish palace secretly built for President Vladimir Putin.

Despite denials from the Kremlin of the investigation's veracity, the film quickly garnered 70 million views.

Ahead of Saturday's rally, police rounded up key Navalny associates from his field offices and sentenced them to short prison stays ranging from nine to 28 days.

However, if the pressure was an attempt to intimidate, rallies of varying size were still held across the country.

In Russia's second city of St. Petersburg, demonstrators overwhelmed police lines and thousands strolled down the city's Nevsky Prospekt.

In the city of Khabarovsk in Russia's Far East, several thousand people attempted to walk down the city's central street before being stopped by riot police.

Similar scenes played out in cities like Irkutsk, Omsk, Yekaterinburg, and Vladivostok.

Even in remote Yakutsk, a northern outpost where temperatures dipped to -50C, several hundred protesters came out to protest in the city's central square. Witness video showed police hailing several protesters into waiting police vans as a heavy frost hung in the air.   

Opposition leader Alexei Navalny is escorted out of a police station on Jan. 18, 2021, in Khimki, outside Moscow, following the court ruling that ordered him jailed for 30 days.

Risky strategy   

Navalny was arrested upon his return to Russia last Sunday, ending a nearly five-month recovery in Germany from a poisoning attack he suffered while traveling in Siberia last August.

The opposition politician insists the assassination attempt was carried out on the orders of Putin, a charge the Russian leader vehemently denies. 

Yet Russian authorities have refused to investigate the incident, preferring to threaten new criminal charges against Navalny instead.

Earlier this week, a judge sentenced Navalny to 30 days in prison pending charges of violating parole while recovering abroad.

Russian opposition leader Alexei Navalny is escorted by police officers after a court hearing, in Khimki outside Moscow, Russia Jan. 18, 2021.
Russian Court Orders Putin Critic Navalny Held for 30 Days
Returning home after poisoning, Alexei Navalny finds a jail cell

The hearing was held in a makeshift courtroom inside the police station, proceedings Navalny labeled as "beyond the height of lawlessness" before calling for Russians to take to the streets in response.

"The way they arrested him was against our constitution," said Ilya, 23, a demonstrator in Moscow.

"If they can do it to a person like Navalny—with millions of followers online—they can do it to us." 

Despite the large turnout, however, it was unclear whether demonstrators had made any progress on their central demand for Navalny's release.

The opposition leader's chief strategist announced a follow up protest would be held again next weekend.

"If enough of us come out, then they'll have to let him go," said Yuri, 22, who was passing out small Russian flags on Pushkin Square in Moscow.

"We're the real patriots of our country. Not those who steal from the people," he added.