Fighting flared between Ukrainian forces and Russian-backed rebels in separate parts of eastern Ukraine overnight, claimed nine lives, Kiev's military and separatist sources said on Monday.
The separatist Donetsk News Agency (DAM) said artillery fire killed three people in a front line town of Horlivka and two in the rebel capital of Donetsk. Ukrainian officials reported two civilian deaths on their side, in a suburb of Mariupol on the Black Sea. The Ukrainian Security and Defense Council also reported two troops killed and six injured overnight.
The clashes, near the port of Mariupol in the southeast and at rebel-held Horlivka, further frayed an increasingly tenuous ceasefire as Ukraine prepared to mark its Independence Day next week.
Kiev accused the separatists of shelling civilians on the outskirts of Mariupol. In Moscow, Russian Foreign Minister Sergei Lavrov blamed Kiev for the violence, giving no detail but saying he suspected Ukraine was preparing a new offensive.
Ukrainian President Petro Poroshenko, meanwhile, accused Russian President Vladimir Putin of trying to whip up tensions in eastern Ukraine by visiting Crimea, which Russia annexed from Ukraine last year. The Kremlin said Putin was promoting tourism on the peninsula.
The escalation has drawn expressions of concern from Western governments, which regard the ceasefire and tentative peace agreement worked out in Minsk, Belarus, in February as still the best chance of ending the rebellion in eastern Ukraine.
Ukrainian military spokesman Andriy Lysenko said the rebels had used howitzers with a range of 10 miles to shell Sartana, on Mariupol's northern edge.
"The enemy was not shelling Ukrainian positions, but a civilian town," he told a briefing. "The enemy has now adopted the tactic of firing and then quickly withdrawing. The next time they'll get a quick response. What has happened in Sartana is a challenge to our forces."
"On one street there were five houses that were really badly damaged by shell fragments. One house had a well-tended garden with vines and a vegetable patch. But the house had been wrecked by shells and I saw an enormous pool of blood," a local news photographer, Mykola Ryabchenko, told Reuters by telephone.
Lysenko said the rebels had used heavy weapons including Grad rockets in attacks on government forces around Horlivka.