The Ukrainian military says the situation has worsened in eastern Ukraine where Russian-backed separatists are battling government forces.
Ukrainian presidential spokesman for military issues Oleksandr Motuzyanyk said on August 22 that the rebels continue to shell Ukrainian government positions with howitzers, cannons, and mortars.
He said eight Ukrainian soldiers had been wounded in fighting in the past day.
Motuzyanyk said the attacks by the separatists were strongest near the southern port city of Mariupol.
He said that near the rebel-held city of Luhansk, shelling was concentrated around the towns of Valuysk, Novotoshkyvske, and Zoloty.
Meanwhile, Ukrainian President Petro Poroshenko said in Kharkiv on August 22 that the "military threat from the East" would be the focus of the country for the "next decade."
He added that by the end of the year Ukraine's army would have 400 extra vehicles and additional military equipment.
Poroshenko will meet with German Chancellor Angela Merkel and French President Francois Hollande in Berlin on August 24 to discuss the implementation of the Minsk cease-fire agreement.
More than 6,400 people have died in the fighting in eastern Ukraine since April 2014.
Based on reporting by Interfax and TASS