German Chancellor Angela Merkel, in a telephone conversation with Russian President Vladimir Putin on December 28, urged him to free 24 Ukrainian sailors who were captured near the Kerch Strait in the Black Sea on November 25.

Read alsoAll 24 Ukrainian sailors captured by Russia declare themselves prisoners of war

Merkel also welcomed the agreement to establish the New Year truce in eastern Ukraine, which was reached within the Trilateral Contact Group (TCG) for the Donbas settlement on December 27, according to the Ukrainian-language service of Germany's Deutsche Welle (DW).

As UNIAN reported earlier, despite the TCG agreement, Russia-backed militants opened fire from grenade launchers on Ukrainian positions near the village of Zalizne on the first day of the New Year truce, starting midnight December 29.

UNIAN memo. On November 25, Russia blocked the passage to the Kerch Strait for the Ukrainian tugboat "Yany Kapu" and two armored naval boats "Berdyansk" and "Nikopol," which were on a scheduled re-deployment from the Black Sea port of Odesa to the Azov Sea port of Mariupol.

The Ukraine Navy Command noted that the Russian side had been informed of the plans to re-deploy the vessels in advance in accordance with international standards to ensure the safety of navigation. The Russian coast guard ship "Don" rammed the Ukrainian tugboat, damaging the Ukrainian vessel. As the Ukrainian boats were heading back in the Odesa direction after being rejected passage via the Kerch Strait, Russian coast guards opened aimed fire on them.

All 24 crew members on board were captured and later remanded in custody for two months, being charged with "illegal border crossing" (the sailors are facing up to six years in prison). Three crewmen were wounded in the attack. Russian-controlled "courts" in occupied Crimea ruled that all 24 detainees should be remanded in custody, after which they were transferred to the Moscow-based Lefortovo and Matrosskaya Tishina detention centers.