A Russian Court sitting in Moscow, on Tuesday ordered the pre-trial detention until April 24, of eight sailors accused of illegally entering Russian waters, Russian news agencies reported.
The sailors are among 24 men captured by Russia when it intercepted and seized three Ukrainian vessels off the Crimean coast in November last year.
The court hearings were closed to the public, but the sailors were shown on state television in the custody of armed security officers in masks.
It was not immediately clear if any others among the 24 would appear in court.
No date has been set for a trial.