Some 70 people were detained in downtown Moscow on Triumfalnaya Square for an attempt to hold an unauthorized rally, Moscow police spokesman Viktor Biryukov said Friday.
There were in fact two rallies. One rally, held by rights advocates, was sanctioned by authorities, the other was not.
"Sixty-eight people, including a number of rally organizers, were detained," Biryukov said.
Police, who earlier cordoned off downtown Moscow's Triumfalnaya Square shortly before two rallies began at 6 p.m. Moscow time (15:00 GMT), said some 300 people took part in the authorized rally, with 200 journalists covering the event.
"All rally participants have now left Triumfalnaya Square," the spokesman said.
The opposition leader of The Other Russia, Eduard Limonov, told Ekho Moskvy radio station earlier Friday that he had been detained at the entrance to his house when leaving ahead of a protest scheduled on Triumfalnaya Square.
Oppositionists Boris Nemtsov and Ilya Yashin were among those detained as well. An Ekho Moskvy correspondent was also held "by mistake" but later released.
A law enforcement source said all those detained are likely to be released before New Year.
The sanctioned protest was led by human rights leader Lyudmila Alekseyeva. Protestors started with shouting slogans in support of jailed former tycoon Mikhail Khodorkovsky.
The Khamovniki District Court in Moscow on Thursday sentenced ex-Yukos CEO Khodorkovsky and his business partner Platon Lebedev to a total of 14 years in prison in the second trial involving Yukos assets. With time already served counting towards this total, both men could remain behind bars until 2017.
Many Western organizations and countries, including the United States and the European Union, have condemned the verdict as harsh and unfair, and expressed concern over the fact that the judicial system in Russia has shown no signs of improvement despite President Dmitry Medvedev's pledge to make it just and transparent.
For more than a year, protesters have attempted to hold rallies on Trimfalnaya Square on the last day of every month that has 31 days to demand that the government respect Article 31 of the Russian Constitution, which guarantees freedom of assembly.
Requests to hold the rallies were invariably turned down by former Moscow mayor Yury Luzhkov, who was dismissed by President Dmitry Medvedev in September.
Current Mayor Sergei Sobyanin sanctioned October's rally, but the event was marred by an inner dispute between the protest's kingpins over the number of participants.
St. Petersburg police said some 50 protestors were detained at an unauthorized protest rally in the northwest Russian city.
MOSCOW, December 31 (RIA Novosti)
