MOSCOW -- Several thousand people commemorated the sixth anniversary of the death of Russian opposition politician Boris Nemtsov in central Moscow.
Opposition supporters laid flowers on the Bolshoi Moskvoretsky Bridge -- a short walk from the Kremlin -- where Nemtsov was gunned down on February 27, 2015.
Nemtsov, a former deputy prime minister who was once seen as a potential successor to President Boris Yeltsin, was an ardent critic of Russian President Vladimir Putin.
Prominent opposition figures who participated in the memorial included: Yabloko co-founder Grigory Yavlinsky; Moscow district council member Ilya Yashin; Moscow City Duma Deputy Yulia Galyamina; activist Vladimir Kara-Murza; presidential Human Rights Council member Nikolai Svanidze; former Prime Minister Mikhail Kasyanov; and the wife of imprisoned opposition leader Aleksei Navalny, Yulia Navalnaya.
"We come together in this place on this day every year to show the authorities that we have not forgotten and will not forget," Kasyanov told AFP on February 27 at the memorial site.
"I am sure that what Boris fought for -- freedom for Russians, their well-being and a dignified life -- will soon come about.”
The ambassadors of several Western countries, including the United States and Britain, were among those who attended the commemoration.
The anniversary is usually marked with a march through central Moscow. But due to restrictions on mass gatherings because of the coronavirus pandemic, opposition activists gathered at a makeshift memorial site on the bridge.
The Bely Schyotchik organization, which tracks attendance at public rallies, estimated the turnout at more than 10,000 people as of 9 p.m. local time with more people still arriving.
Nationwide Memorials
Smaller memorial gatherings were held in other Russian cities, including in Nizhny Novgorod where Nemtsov served as the popular governor in the 1990s.
In St. Petersburg, several hundred people paid their respects to Nemtsov in front of a large contingent of riot police.
In Krasnodar, municipal workers cleared away a makeshift memorial less than half an hour after it was installed. Several memorial participants were reportedly detained.
U.S. Embassy spokeswoman Rebecca Ross tweeted that U.S. Ambassador John Sullivan had marked the "brutal murder" of Nemtsov, whom she described as having been "dedicated to pursuing a better future for his country."
"He remains an inspiration to many who strive for justice, transparency, freedom," she tweeted.
"As we remember Nemtsov, we reaffirm our unwavering commitment to human rights and fundamental freedoms," U.S. Secretary of State Antony Blinken said in a statement. "We remain deeply troubled by the Russian government's growing intolerance of all forms of independent expression."
The anniversary of Nemtsov’s death comes after Russia’s jailing of opposition political leader Aleksei Navalny and a crackdown on his allies.
Last week, a Moscow court upheld a 2 1/2 year prison sentence imposed on Navalny earlier in February for a parole violation related to a previous embezzlement conviction.
The Russian opposition called on supporters to gather at the Bolshoi Moskvoretsky Bridge to pay tribute to Nemtsov, but not to rally.
Navalny's allies have declared a pause on protests until spring after authorities responded forcefully to a wave of national demonstrations, detaining more than 10,000 people in dozens of cities and filing administrative and criminal cases against many of them.
Last week, a Moscow court upheld a 2 1/2 year prison sentence imposed on Navalny earlier in February for a parole violation related to a previous embezzlement conviction.
The opposition said it planned a “memorial event,” not a rally, to pay tribute to Nemtsov on February 27.
WATCH: Battle Goes On For 'Nemtsov Bridge' Memorial
Moscow authorities rejected a request for opposition supporters to hold a commemorative march due to the coronavirus pandemic.
On February 27, the Boris Nemtsov Foundation For Freedom awarded Navalny the Boris Nemtsov Prize for Courage.
In a statement, it said “Navalny has not only demonstrated incredible personal courage, but has also made an outstanding contribution to exposing corruption and increasing citizens’ engagement in Russia’s still-existing political procedures.”
The foundation called for the “immediate release” of the 44-year-old.
Supporters of Nemtsov have maintained a makeshift memorial on Bolshoi Moskvoretsky Bridge ever since his death despite police, city workers, and others regularly destroying or removing it. A volunteer died in August 2017 after he was beaten on the bridge.
Five Chechens have been found guilty of involvement in his killing, but the Russian authorities have failed to determine who ordered it.