The European Union has criticized an "unprecedented level of violence" in eastern Ukraine after international monitors came under fire.
"The significant increase of cease-fire violations in the Donetsk region represents an unprecedented level of violence," EU foreign policy chief Federica Mogherini said in a statement on April 10.
The Organization for Security and Cooperation in Europe (OSCE) said late on April 9 that a team of its monitors in eastern Ukraine had come under fire 50 kilometers south of Donetsk.
There were no injuries in the incident.
OSCE observers were also shot at on April 7 and, on the same day, another monitoring group was threatened at gunpoint by a rebel, forcing the observers to leave a checkpoint they needed to pass.
The OSCE has said that it had observed a "significantly higher number of cease-fire violations" in the Donetsk region.
Mogherini added that "a sustainable ceasefire is urgently needed."
More than 9,100 people have been killed in the fighting in Ukraine's eastern Donbas region and some 21,000 wounded since the conflict broke out in 2014.
Based on reporting by AFP and dpa