Western nations and Russia traded accusations at the United Nations on Friday over the recent upsurge in violence in eastern Ukraine, while a senior member of an international monitoring team blamed both sides in the conflict for breaking a ceasefire.
The diplomatic clash between European, U.S. and Russian envoys came a day after Ukraine warned of a possible "full-scale invasion" by Russia, following the worst fighting with Russian-backed separatists in months.
The deputy head of the Organization for Security and Cooperation in Europe's (OSCE) monitoring mission, Alexander Hug, was more balanced in his remarks to the Security Council. He said both sides of the conflict were putting civilians at risk as the security situation deteriorates.
"Civilians continue to bear an unacceptable price in this conflict," Hug told an emergency meeting of the 15-nation council. "They are killed and wounded, as both sides continue to place military positions in and around civilian infrastructure. Their property and livelihoods have been destroyed."
Britain placed the blame for the new violence squarely on Moscow.
"This was a separatist assault on Ukrainian military units," said British Ambassador Matthew Rycroft, adding that it was "clearly premeditated."
"The separatist forces are Russia's creation, they are Russia's tool," he said. "Russia has the capacity and the influence to control the separatist forces. It must exercise that influence to ensure compliance with the Minsk agreements."
He was referring to a ceasefire agreement clinched in February in the Belarusian capital.
Russian Ambassador Vitaly Churkin presented the opposite view. He blamed the latest fighting on Kiev, saying it was violating the Minsk agreement and putting civilians at risk.
Members of the Ukrainian armed forces patrol the area in the town of Maryinka, eastern Ukraine, June 5, 2015.
"If we allow Kiev to continue... the situation could fall out of control," he said.
U.S. Ambassador Samantha Power cited Twitter announcements by separatist fighters boasting of a successful attack on Marinka, Ukraine. She said Russia continues to deny the "open secret" that it arms the rebels and sends Russian soldiers to die anonymously in neighboring Ukraine.
French Ambassador Francois Delattre echoed Power's remarks: "Everyone knows the role that they've (Russia) been playing in this crisis since the start."
The ambassadors of Lithuania and Ukraine said Kiev had a right to defend itself against the Russian-backed rebels.
Kiev and its NATO allies accuse Russia of sending weapons and troops to fight on behalf of separatists who control part of two provinces in its east. Moscow, which seized and annexed Ukraine's Crimea peninsula last year, denies its troops are participating.