Intense fighting flared in eastern Ukraine over the last three days, shattering a cease-fire that held for two months while winter snow dampened the year-old conflict and the early spring thaw mired the would-be combatants in vast expanses of mud.
At least six Ukrainian government soldiers were killed in the 24 hours before noon on Tuesday, Col. Andriy Lysenko of the National Security and Defense Council told reporters in Kiev, the capital. Twelve others were injured, he added.
A leader of the pro-Russia separatists occupying two industrial regions of eastern Ukraine said one of its fighters had been killed late Monday, when artillery barrages erupted near the rebel stronghold of Donetsk.
A Russian journalist with the Zvezda television channel was seriously injured by what appeared to be a land mine detonation while on a media visit to the town of Shyrokyne led by monitors of the Organization for Security and Cooperation in Europe, the BBC correspondent on the trip reported.
"We were told by the pro-Russian rebels, who guided us and other journalists, that things were quiet in the village of Shyrokyne, near the strategic port city of Mariupol. But within minutes of arriving, there are loud explosions," the BBC's Tom Burridge reported from the scene. "A man lies seriously wounded on the ground. He's bleeding badly from the head."
The injured journalist was identified by the Associated Press as Andrei Lunev, a videographer for the Russian military news station. He was taken to a nearby hospital where he was reported in serious but stable condition.
Fighting had largely subsided in eastern Ukraine after a Feb. 12 peace plan was brokered by European mediators in the Belarus capital of Minsk. A cease-fire that went into effect three days later took hold after the separatists wrested the railway hub of Debaltseve from the government's control but the lull was seen as a bow to the region's brutal winter weather as much as a desire on either side's part to end the conflict that has taken more than 6,000 lives.
The European security agency, which has more than 300 monitors deployed in Ukraine to report cease-fire violations and other disruptions, issued a warning Sunday night that fighting was intensifying.
The monitors "observed that an intensive armed clash was underway with the use of tanks, heavy artillery, automatic grenade launchers, mortars, heavy machine-guns, and small arms and light weapons," the agency said, adding that the monitors recorded 1,166 explosions over a five-hour period Sunday.
The weekend flareup prompted a meeting in Berlin on Monday of what is called the Trilateral Contact Group, drawing together the foreign ministers of Ukraine, Russia and the European security agency members Germany and France. They issued an appeal for renewed commitment to the cease-fire and additional measures to withdraw heavy weaponry beyond what was required by the Minsk agreement.
Spokesmen for both the Moscow-backed separatists and the Ukrainian government forces accused their opponents of massing heavy artillery for a major confrontation.
Pro-Russia gunmen seized government and security buildings in Donetsk and Luhansk regions in April 2014 after Russia annexed Ukraine's
The latest fighting has focused on Shyrokyne, a frontline town on the road along Ukraine's Sea of Azov that Russia is believed to covet as a supply route to Crimea.