BRUSSELS -- The European Union has expressed deep concern over reports of military convoys moving westward on rebel-controlled territory in eastern Ukraine and urged Russia to withdraw any troops or weapons under its control from the neighboring country.
"The most recent reports by the OSCE [Organization for Security and Cooperation in Europe] Special Monitoring Mission in Ukraine about convoys in separatist held areas with substantial amounts of heavy weapons, tanks and troops without insignia moving westwards represent a very worrying development," EU foreign policy chief Federica Mogherini said in a statement on November 9.
Mogherini's statement came a day after the OSCE said its monitors had observed "convoys of heavy weapons and tanks," in Donetsk, one of two provincial capitals held by pro-Russian separatists, and the nearby town of Makiivka.
It adds to Western pressure on Russian President Vladimir Putin, who denies Moscow has lent military support to separatists fighting to carve out states in eastern Ukraine in a conflict that has killed more than 4,000 people since April.
Putin will see U.S. President Barack Obama at an Asia-Pacific summit in Beijing on November 10-11 and come face-to-face with several Western leaders at a G20 summit in Australia on November 15-16.
The United States and European Union have condemned elections held by the pro-Russian separatists on November 2 as illegitimate, amid concerns that the votes have solidified the control of separatists -- and Moscow -- over sections of eastern Ukraine.
Demanding that all parties adhere to a September 5 cease-fire and seek a solution that would respect Ukraine's territorial integrity, Mogherini urged Russia to "fully assume its responsibilities in this regard."
That means "preventing any further movement of military, weapons or fighters from its territory into Ukraine, and withdrawing any troops, weapons and equipment under its control from Ukraine," she said.
She said Russia should be "exercising its influence to ensure that the separatists implement in good faith the obligations assumed in Minsk," a reference to the truce and steps to peace agreed in the Belarusian capital on September 5.
The EU foreign policy chief also expressed concern over "reported heavy outgoing shelling overnight from the Donetsk area and reports over the last week of increased movements of troops and equipment."
Reporters from the AFP news agency in the area of Donetsk said that intense artillery fire erupted inside the city early on November 9.
The OSCE report on the convoys came on November 8, the same day that the AP news agency said its reporters had seen more than 80 unmarked military vehicles near Donetsk.
A tweet from an AP reporter apparently showing a large military convoy in eastern Ukraine on November 8.
A day earlier, Ukraine's military accused Russia of sending a column of 32 tanks and truckloads of troops into the country's east to support pro-Russian separatists fighting government forces.
The OSCE monitors said that "More than 40 trucks and tankers" were seen driving on a highway on the eastern outskirts of Makiivka.
The OSCE said that 19 of these were large trucks without markings or number plates, and carrying personnel in dark green uniforms as well as towing howitzers.
Separately, the OSCE monitors also said they had seen "a convoy of nine tanks -- four T72 and five T64 -- moving west, also unmarked," just southwest of Donetsk.
Ukraine said it had no doubt the troops, tanks, and trucks were Russian.
"Although the OSCE did not specify to whom the equipment and soldiers belonged, the Ukrainian military has no doubt of their identity," Ukrainian military spokesman Andriy Lysenko said on November 9.
"The past week was characterized by an increase in the intensity of shelling and the transfer of additional force: ammunition, equipment and personnel, to terrorist groups," Lysenko said.
The Swiss foreign minister and OSCE chairperson-in-office, Didier Burkhalter, said on November 8 that he was "very concerned about a resurgence of violence in the eastern regions of Ukraine."
"He urged all sides to act responsibly and to do all in their power to further consolidate the cease-fire," the OSCE said in a statement.
The OSCE monitors have been tasked with monitoring the shaky cease-fire signed by Kyiv and the pro-Russia separatists in Minsk in September.
AP said its reporters had taken photos and video of three columns of armed vehicles and other military hardware: one near Donetsk and two near the town of Snizhne.
Most of the vehicles were transport trucks but there was at least one armored personnel carrier.
AP said several of the trucks were carrying troops.
Based on reporting by Rikard Jozwiak in Brussels with additional material from Reuters, AP, and AFP.