Opposition activists are planning a March of Dissent rally in the city on May 18. The rally will coincide with a Russia-EU summit in Samara.
Lyudmila Alekseyeva, head of the Moscow Helsinki Group, says members of her organization will collect information about Russian authorities' compliance with human rights laws and treaties during the march.
Police last month quashed March of Dissent rallies in Moscow and St. Petersburg, detaining more than 200 demonstrators.
In Samara on May 11, police detained a group of journalists for several hours for what they said was an identity check while the journalists were reporting on preparations for the upcoming rally.