Russian-backed rebels on Sunday did not adhere to a truce agreed by European leaders, Russian President Vladimir Putin and Ukrainian President Petro Poroshenko, saying the truce doesn't apply to the town they believe they hold.
The truce appeared to take hold in other parts of the country, but not in Debaltseve in eastern Ukraine. "Of course we can open fire [on Debaltseve]. It is our territory," Eduard Basurin, a senior rebel commander, told Reuters.
"The territory is internal: ours. And internal is internal. But along the line of confrontation there is no shooting."
Reuters reporters said they heard gunfire and artillery from the direction of Debaltseve, which lies between the two main rebel strongholds, separatist-held Donetsk and Luhansk.
The ceasefire is being monitored by Under the Organization for Security and Cooperation in Europe, but Ukrainian Foreign Minister Pavlo Klimkin said Sunday that rebels won't let those observers in Debaltseve.
"It quite clearly shows who is in breach of the Minsk agreement," Klimkin told the Associated Press.
Elsewhere in eastern Ukraine, the guns fell silent at midnight. Up next if the truce moves foward: A neutral buffer zone will be created and heavy weapons will be withdrawn.
Secretary of State John Kerry, in a phone call with Russian counterpart Sergei Lavrov, urged Russia to adhere to the ceasefire. President Obama is in California and played golf for seven hours on Saturday.