Almost a million and a half people turned out in central Moscow on Monday for the annual May Day parade, many more than in past years, Russian police said.
"Nearly 1.5 million people marched on May 1," police said in a statement quoted by Interfax news agency.
Under clear skies, marchers waving flags and carrying balloons poured onto Red Square by the Kremlin. Only 100,000 people took part in the annual Labour Day march in 2015 and 2016, police figures showed.
Some of the marchers waved communist flags and pictures of Soviet founding father Lenin in memory of the old days.
Vladimir Nikolayevich, a war veteran marching in uniform, described the May Day parade as an "immortal" event.
Other marchers chanted anti-government slogans. Vladislav Ryazantsev, a leader of the Left Block movement, said "we are against (President Vladimir) Putin, but not as a person."
In all some 2.6 million Russians joined May Day marches across the country on Monday, authorities said.