Russian security forces have detained eight Crimean Tatar activists in raids on their homes in Russian-annexed Crimea, local media said Monday.

Russian Federal Security Service (FSB) officers detained suspects in the districts of Alushta, Bilohirsk and Simferopol, security service sources said, claiming that the suspects were members of a terrorist organization.

The prosecutor's office in the Crimean Autonomous Region which operates in Ukraine has launched a criminal investigation into the incident.

In late March, the FSB detained 20 Crimean Tatars, also on suspicion of being members of Hizb ut-Tahrir, a group branded as a terrorist organization by Russia, following house-to-house searches in Simferopol -- the regional capital and home to many Crimean Tatars – and in nearby districts.

Crimean Tatars are a Muslim community indigenous to the Black Sea peninsula.

Under Josef Stalin's rule, they were sent into exile to Uzbekistan and the Urals and did not return until the fall of the USSR.

Most Crimean Tatars opposed Moscow's annexation of the Crimean peninsula in 2014 and subsequently Russian authorities have cracked down on the community, banning their assembly and television channel as well as detaining and jailing dozens of activists.