Ukrainian authorities say eight military personnel have been captured by Russia-backed fighters in the eastern region of Donetsk.
Ukraine’s Joint Forces Operations (OOS) in the country's east said in a statement that the soldiers were captured on May 22.
"According to preliminary information, early in the morning today, eight military personnel of Ukraine's armed forces from the OOS took a wrong turn while moving aboard a truck near the town of Novotroyitske and found themselves in temporarily occupied territory, where they were captured by fighters of the Russian Federation's armed forces," the OOS statement said.
The Ukrainian military frequently refers to Russia-backed separatist forces who hold parts of the Donetsk and Luhansk regions as "fighters of the Russian Federation's armed forces."
It also says that many regular Russian soldiers have fought in the conflict there, a claim that Moscow denies despite what Kyiv and NATO say is incontrovertible evidence.
Ukraine’s Defense Ministry said earlier in the day that three soldiers were wounded in five cease-fire violations by Russia-backed forces over the previous 24 hours.
The separatists in turn accused government forces of violating the cease-fire twice since May 21.
Some 13,000 people have been killed in the conflict in eastern Ukraine since April 2014, when Russia encouraged separatism following the downfall of Moscow-friendly Ukrainian President Viktor Yanukovych.
Cease-fire deals 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.
A new cease-fire agreement was reached on March 8, but both sides have accused each other of repeated violations since then.
The conflict in the region known as the Donbas is one of the challenges facing President Volodymyr Zelenskiy, who was inaugurated on May 20.