UN Secretary-General Ban Ki- moon has said he is dismayed by the deadly overnight attack against a military checkpoint in eastern Ukraine.
With three days before presidential elections, Ban appealed in a statement Thursday to all parties to "redouble their efforts and help create the necessary conditions so that all eligible voters throughout the country may cast their ballots in a free and fair environment and without fear for their safety", Xinhua reported.
Voters across Ukraine should see the elections as an opportunity to help move the country on to a "more inclusive and stable trajectory while also determining the country's leadership at a pivotal moment", he said.
At least 13 Ukrainian soldiers were killed in the rebel attack at a Ukrainian military checkpoint in the eastern Donetsk region early Thursday.
The presidential election in Ukraine is scheduled for May 25. The attack has triggered fears of possible disruption of the vote in the eastern part of the country.