Ukraine's military on July 22 said that two soldiers were killed and as many wounded on the previous day when an unknown explosive device was set off by an "enemy sabotage and reconnaissance group."
The casualties in the armed conflict with Russia-backed separatists came on the first day when a cease-fire was supposed to go into effect based on an agreement in Minsk on July 17 between Ukrainian and Russian envoys as well as members of the Organization for Security and Cooperation in Europe (OSCE).
Cease-fire road maps announced as part of the Minsk accords -- September 2014 and February 2015 pacts aimed at resolving the conflict -- have contributed to a decrease in fighting but have failed to hold.
The OSCE recorded 75 cease-fire violations through 4 p.m. on July 21.
They included "three explosions, 21 projectiles in flight, and 51 shots of heavy machine-gun and small-arms fire," the OSCE said in a report.
About 13,000 people have been killed in the conflict since April 2014 when Moscow-backed separatists took up arms against Ukrainian government forces. An additional 1.5 million people have been internally displaced, the largest displacement of people on the European continent since World War II.