MOSCOW -- A Moscow court has prolonged the pretrial detention for 12 of 24 Ukrainian sailors detained by Russian forces who attacked three Ukrainian Navy vessels in the Black Sea in November.

In a series of rulings on January 15, the Lefortovo district court granted requests by the Russian Investigative Committee to keep commander Denys Hrytsenko, Security Service (SBU) officer Andriy Drach, and 10 sailors in jail until April 24.

As Russian security officers escorted some of the sailors from the courtroom during a break in the proceedings for lunch, some spectators chanted "Glory to Ukraine!"

The court was expected to issue identical rulings for the other 12 sailors later in the day. All 24 said they considered themselves prisoners of war.

Russia has held the Ukrainian sailors since its forces fired on, boarded, and seized their vessels near the Kerch Strait, which links the Black Sea and the Sea of Azov, on November 25.

Moscow claims the Ukrainian vessels illegally entered Russian territorial waters near Crimea, the Ukrainian peninsula that Russia occupied and took over in 2014.

The sailors have been charged with illegal border crossing and face up to six years in prison if convicted.

The court rulings come five days the European Union reiterated its call on Moscow to release the sailors and all other Ukrainians whom Brussels says have been "illegally detained" in Russia and Crimea.

The United States and other Western countries have also called for their release. U.S. national-security adviser John Bolton said in December that there will be no substantial meeting between President Donald Trump and Russian President Vladimir Putin while Moscow still holds the Ukrainian ships and sailors.

Russia moved swiftly to seize control over Crimea after Moscow-friendly Ukrainian President Viktor Yanukovych was pushed from power in Kyiv by the pro-European Maidan protest movement in February 2014.

Putin's government sent troops without insignia to the peninsula, seized key buildings, took control of the regional legislature, and staged a referendum denounced as illegitimate by at least 100 countries at the UN.

Russia also fomented unrest and backed opponents of Kyiv in eastern Ukraine, where more than 10,300 people have been killed in the ensuing conflict since April 2014.

The International Criminal Court ruled in November 2016 that the fighting in eastern Ukraine was "an international armed conflict between Ukraine and the Russian Federation."