Two Ukrainian soldiers were killed and three others wounded by a land-mine explosion in the eastern Luhansk region.
Hennadiy Moskal, the Ukrainian head of the Luhansk region, said on May 4 that a Ukrainian military vehicle drove over a mine near the village of Yekaterinivka the previous day.
Moskal said the two men were killed instantly by the blast, which occurred in Luhansk's Popasne district.
A southern portion of Ukraine's Luhansk region is controlled by Russian-backed separatists.
Meanwhile, senior rebel official Eduard Baturin told local reporters that one separatist fighter was killed and six more were injured in fighting.
More than 6,100 people have been killed in fighting between Ukrainian soldiers and rebel fighters in eastern Ukraine in the past year, despite the signing of a cease-fire agreement in February.