Ukrainian officials say four soldiers have been killed and 14 wounded in recent fighting in eastern Ukraine.
Military spokesman Oleksandr Motuzyanyk said on August 20 that the casualties occurred in the Luhansk region, part of which is controlled by Russian-backed separatists.
The deaths are part of an upsurge in fighting that began last week in neighboring Donetsk and caused the deaths of 10 people -- both Ukrainian soldiers and separatists -- on August 16 in the Donetsk region.
Meanwhile, an adviser to the Ukrainian Defense Ministry said on August 20 that four Ukrainian soldiers had been released by the rebels.
Vasiliy Budik wrote on Facebook that the release occurred after lengthy negotiations with rebel representatives that included UN officials.
Iryna Herashchenko, a Ukrainian representative in the Trilateral Contact Group, said there are still some 167 Ukrainian soldiers and civilians being held against their will by separatist forces in the Luhansk and Donetsk regions.
The UN says more than 6,400 people have been killed in fighting in eastern Ukraine since April 2014.
Based on reporting by AFP and Interfax