The U.S. State Department has condemned the arrests of 23 Crimean Tatars in Russian-annexed Crimea.
In a March 28 Twitter statement, State Department deputy spokesman Robert Palladino called on Russia to release the arrested men "and the 70+ other unjustly imprisoned Ukrainians."
A court in the Crimean capital, Simferopol, said on March 29 that since March 27, 23 Crimean Tatars had been arrested and placed in pretrial detention until May 15, on charges of belonging to the banned Hizb ut-Tahrir Islamic group.
Crimean Solidarity, a human rights group that has members in Crimea and other parts of Ukraine, said earlier that at least 25 homes of Crimean Tatars were searched on March 27 in Simferopol, and nearby districts.
Since Russia seized the Ukrainian peninsula in 2014, Russian authorities have prosecuted 31 Crimean Tatars for allegedly belonging to Hizb ut-Tahrir.
In February, the branch of Russia's Federal Security Service (FSB) in the Black Sea region launched probes against eight alleged members of the group accused of plotting to seize power in Crimea.
Hizb ut-Tahrir is a global organization based in London that seeks to unite all Muslim countries into an Islamic caliphate.
The group can operate legally in Ukraine. However, Russia's Supreme Court banned it in 2003, branding its supporters "extremists."
Rights groups and Western governments have denounced what they describe as a campaign of repression by the Russian-imposed authorities in Crimea who are targeting members of the Turkic-speaking Crimean Tatar community and others who have spoken out against Moscow's takeover of the peninsula.
Russia took control of Crimea from Ukraine in March 2014 after sending in troops, seizing key facilities, and staging a referendum dismissed as illegal by at least 100 countries. Moscow also backs separatists in a war against government forces that has killed some 13,000 people in eastern Ukraine since April 2014.