Kiev, Ukraine (CNN) -- Twenty Ukrainian prisoners of war have been released under the ceasefire between Kiev and pro-Russian rebels signed in Minsk, Belarus, last week, Ukraine's President Petro Poroshenko said Monday. Ukraine's counterterrorist operation press office said the freed prisoners were Ukrainian troops, telling CNN they had been exchanged for a "terrorist." Speaking in the port city of Mariupol, south of Donetsk, Poroshenko said 33 Ukrainian servicemen who had refused to surrender had also been able to leave the conflict zone. The Russian state news agency ITAR-Tass quoted the vice premier of the self-proclaimed Donetsk People's Republic, Andrei Purgin, as saying both sides had agreed to exchange "30 for 30" prisoners as a starting point.
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NEW: The European Council formally adopts further sanctions against Russia on Monday
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Ukraine and rebels confirm a prisoner release under the Minsk truce agreement
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The Kremlin says the Ukrainian and Russian presidents discussed the truce Monday
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Ukrainian President Petro Poroshenko confirms death of one soldier, one civilian
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