Pro-Russia separatists and Ukrainian government forces fought their most intense battles in months on Wednesday after both sides were reported last week to have looted the internationally monitored depots where their heavy artillery had been stored.
The rebels holding two large regions of eastern Ukraine lost 15 fighters in the battle for government-controlled Maryinka, separatist militia spokesman Eduard Basurin was quoted as saying by Russia's Tass news agency.
Ukrainian forces succeeded in maintaining control of Maryinka after the 12-hour battle, Col. Andriy Lysenko of the National Security and Defense Council told journalists in Kiev, the capital. He blamed the Moscow-backed rebels for the attack on the town once home to nearly 10,000, just west of the separatist stronghold of Donetsk.
Another government military spokesman, Oleksandr Poroniuk of the Anti-Terrorist Operation press center, said Maryinka was still ablaze when fighting subsided Wednesday afternoon.
The intense artillery exchanges knocked out electricity in the region, trapping more than 900 miners underground in the Skochinsky and Zasyadko mines in Donetsk early Wednesday, Basurin told reporters in Donetsk. Evacuations were underway, he said.
Fighting also broke out along other areas of the front lines that were purportedly frozen after a Feb. 12 peace plan was brokered in the Belarus capital of Minsk. A cease-fire took effect three days later, although it has been violated almost daily, and the two sides partially complied with a mid-March timetable for surrendering their tanks, heavy guns and rocket launchers to depots that were supposed to be monitored by the Organization for Security and Cooperation in Europe.
But the daily OSCE monitoring mission report for Saturday noted that a multinational team from the 57-nation security agency had been denied access to two of the five separatist weapons caches and that the inspectors found dozens of heavy weapons missing from two others and the fifth depot entirely emptied.
The monitors also reported being delayed in their attempts to inspect three government-held weapons storage facilities and, when allowed in after the delays, found weapons missing from one of them.
Ukrainian military spokesman Oleksiy Mazepa was quoted by Interfax-Ukraine news agency as saying government forces "were forced to use heavy artillery" to defend against the separatist attack on Maryinka.
Russia's Sputnik news agency reported the Kiev government's acknowledgment of having used heavy artillery in violation of the Minsk peace plan but made no mention of the rebels' retaking their own surrendered guns and armor.
More than 6,400 people have been killed in eastern Ukraine since April 2014, when separatists opposed to a new government in Kiev seized the Donetsk and Luhansk regional administration buildings and waged a war for territory between the border with Russia and the Black Sea.
The fighting in eastern Ukraine was sparked after Russian President Vladimir Putin seized and annexed Ukraine's Crimean peninsula. The forcible change of borders has been condemned by most of the international community and prompted the United States and the European Union to impose sanctions on Moscow.