Ukraine has said its forces have been fighting an armored column that crossed into the country from Russia. Meanwhile, Moscow has announced plans to sent a second aid convoy to eastern Ukraine.
Ukrainian military spokesman Andriy Lysenko told reporters on Monday that government forces had intercepted a column of 10 tanks, two armored vehicles and two trucks after they had crossed into the east of the country from Russia.
"This morning there was an attempt by the Russian military in the guise of Donbas fighters to open a new area of military confrontation in the southern Donetsk region," military spokesman Andriy Lysenko said.
He said these were Russian vehicles bearing the flags of pro-Russia separatist rebels. He also said shells had been fired from Russian territory at the nearby city of Novoazovsk. There was no independent confirmation of the Ukrainian military's claims.
Ukrainian President Petro Poroshenko used a telephone conversation with the president of the European Council, Herman Van Rompuy, to express his concerns about the latest developments in the east of the country.
"Ukraine's head of state expressed his extreme concern about the breaching of Ukraine's border by Russian armoured vehicles and Russia's intention to send a so-called 'humanitarian' convoy again to Ukraine," a statement released by Poroshenko's office said.
This came just hours after Russian Foreign Minister Sergei Lavrov announced that Moscow planned to send a second aid convoy to eastern Ukraine, where government forces are battling pro-Russia rebels.
"We want to reach an agreement on all conditions for delivering a second convoy by the same route," Lavrov told reporters in Moscow.
Lavrov also denied any knowledge of a military column crossing into eastern Ukraine from Russia.
Last Friday, a Russian aid convoy crossed the border into eastern Ukraine without Kyiv's approval, delivering supplies to the separatist-stronghold of Luhansk. The Ukrainian government denounced the move as an "invasion."
Kyiv had earlier expressed fears that the 260-truck convoy would be used to resupply the rebels with arms and munitions. Moscow said that the convoy only contained humanitarian aid for civilians who have been caught up in the fighting.
The latest developments come a day before both Ukrainian President Poroshenko and his Russian counterpart, Vladimir Putin, are to be among several leaders meeting in the Belarusian capital, Minsk. It was unclear whether the two men would meet one-on-one to discuss the crisis.
At his press conference in Moscow, Lavrov said he hoped European Union officials "will come prepared to use their influence on the Ukrainian side."
Kyiv and the West accuse the Kremlin of supporting the pro-Russia rebels in eastern Ukraine, a charge Moscow has repeatedly denied.
pfd/tj (AFP, Reuters, AP)