Russians in Moscow and other cities across the country have protested against the prospect of transferring the disputed Kurile Islands to Japan.
The January 20 protest on Suvorovskaya Square, just outside Moscow city center, was sanctioned by authorities and was organized by a coalition of groups including Left Front, the Party of Action, the Other Russia, Novorossia, and other left-leaning and nationalist organizations.
Organizers said some 2,000 people showed up for the Moscow protest, while municipal officials put the figure at 500.
The Soviet Union seized the four southernmost Kurile Islands from Japan in the closing days of World War II. The dispute over them has prevented the two countries from signing a peace treaty formally ending the hostilities.
In November, Russian President Vladimir Putin and Japanese Prime Minister Shinzo Abe agreed to accelerate negotiations based on a 1956 Soviet proposal to return the two less populated islands, Shikotan, and a group of islets called Habomai.
"Any mention of handing over the Kuriles…is nothing but an act of treason," speaker Igor Skurlatov told the rally in Moscow, during which the participants chanted slogans such as, "The Kuriles are Russian soil."
"Today we give away the Kuriles, tomorrow we give away Crimea," he added, referring to the Ukrainian region that Russia occupied and annexed in 2014.
Left Front leader Sergei Udaltsov posted photographs from the Moscow protest on Twitter, saying the demonstrators "were actively chanting patriotic slogans."
In the Far Eastern city of Khabarovsk, about 500 people participated in the demonstration chanting the slogan, "The Kuriles are ours! Down with Putin's government."
Small demonstrations were reported in the Far Eastern port of Nakhodka and the western exclave of Kaliningrad.
On January 19, about 300 people demonstrated in the city of Yuzhno-Sakhalinsk, the capital of the Far Eastern island of Sakhalin.
Putin was set to hold talks on the territorial dispute with Abe in Moscow on January 22, according to the Kremlin, following a meeting last week between foreign ministers Sergei Lavrov and Taro Kono.
In remarks both before and after the January 14 talks with Kono, Lavrov said the two countries still had "substantial disagreements" despite some progress in bringing their positions closer.
Lavrov also warned not to expect progress toward an agreement unless Japan first recognizes Russian sovereignty over “all the islands of the Southern Kuriles.”