Russian activist rock band Pussy Riot claimed responsibility on Sunday for the pitch invasion that briefly interrupted the World Cup final in Moscow.
Just after Croatia goalkeeper Danijel Subasic saved a shot from Kylian Mbappe in the 51st minute, three women and one man emerged into the run of play from the other end of the stadium. One made it to the centre circle.
Dressed in suits and what appeared to be old-fashioned police uniforms, the pitch invaders approached players. One woman shared a double high-five with Mbappe, while Croatia defender Dejan Lovren pushed the man, helping a steward to detain him.
The invaders were quickly tackled by security, and the match resumed after a delay of about 1 minute while France were leading 2-1.
Pussy Riot, long a thorn in the side of Russian President Vladimir Putin, released a statement on social media after the incident to say the action was a protest. The band issued a list of demands to the Russian government, including to free political prisoners, end "illegal arrests at protests" and to "allow political competition in the country."
The statement also referenced the case of Oleg Sentsov, a vocal opponent of Russia's annexation of Crimea from Ukraine in 2014, who was sentenced in 2015 to 20 years for conspiracy to commit terror acts. He denies the charges and has been on a hunger strike since mid-May.
The group said the police uniforms symbolised how Russian police's actions fall short of their "heavenly" depiction in literature and called for reforms. It wasn't clear if they used the uniforms as a ruse to enter Luzhniki Stadium amid tight security.
Pussy Riot member Olga Kurachyova told Reuters she was one of the pitch invaders and was being held at Luzhniki police station. She said she could not speak further because police were trying to take her mobile phone away from her.
"The citizens in question were taken to the local police station,'' the Moscow branch of the Russian Interior Ministry said. FIFA did not immediately respond to a request for comment. The event's local organising committee said it did not have further information.
Police said they were investigating the four on suspicion of violating rules for spectating at a sporting event -- which carries a maximum fine of up to 10,000 roubles ($160) or 160 hours' community service with a ban on attending sports events of up to three years -- as well as illegally wearing a police uniform, which carries a fine of 1,000 to 1,500 roubles.
A video circulated on Russian social media and retweeted by the band after the match appeared to show two of the protesters, still in police uniforms, being harshly interrogated at a police station. The independent television channel Dozhd identified one of them as Pyotr Verzilov, who is married to Pussy Riot member Nadezhda Tolokonnikova.
Under barking queries from a man off-camera, Verzilov says: "I am for Russia, just like you -- if you are for Russia." The man off-screen responds: "I sometimes wish it was 1937" -- referring to the year in which Stalinist purges were at their height.
The balaclava-clad women of Pussy Riot rose to global prominence with their daring outdoor performances critical of Putin in 2012 that sent two members to prison for nearly two years. They were released three months early in December 2013 under an amnesty to mark the 20th anniversary of Russia's constitution.
In 2016, the group also released a music video criticising Russia's staging of the Winter Olympics in Sochi. The video included clips from an incident in the city when Cossacks beat activists with a whip as they tried to perform a song beside a wall covered in the Olympic logo.
The pitch invasion was the first significant security lapse in the five-week tournament that has won hosts Russia widespread praise for organisation and efficiency. Putin was watching the game alongside his French and Croatian counterparts and FIFA president Gianni Infantino, among other dignitaries.
The protest was briefly shown on international TV broadcasts, even though FIFA policy is usually to cut away when fans and others run onto the field.
Lovren told reporters the incident had interrupted the game at an important moment for his team as Croatia wen on to lose 4-2.
"We'd been playing good football and then some interruption came," he said. "I just lost my head and I grabbed the guy and I wished I could throw him away from the stadium."
Information from The Associated Press and Reuters was used in this report.