KIEV, Ukraine — Ukraine warned Thursday that the security situation is steadily worsening in the country's rebel-held east as separatist fighters move closer to government forces. One official said he feared an attack soon by Russian forces.
A cease-fire agreed upon in September between the pro-Russian rebels and Ukraine's government in Kiev has been violated daily, especially around areas coveted by both sides like the airport in the eastern city of Donetsk.
National Security and Defense Council spokesman Andriy Lysenko said the Russian army is massing troops, including air defense units, near the border. Ukraine for months has accused Russia of directly supplying the separatist forces.
Russian Foreign Ministry spokesman Alexander Lukashevich denied the Ukrainian charge.
"There have been and are no military movements across the border or, all the more, any presence of our troops in the southeast of Ukraine," he said Thursday in Moscow.
Ukraine's warnings of possible renewed hostilities follow multiple recent observations of large military convoys on the move around the country's eastern separatist-controlled areas. Trucks transporting troops, ammunition, fuel and large-caliber artillery systems have been seen traveling primarily in the direction of Donetsk, the main rebel-held city.
Ukraine and NATO have said they believe the equipment has been delivered from Russia, although they have yet to provide conclusive evidence for that.
Monitors from the Organization for Security and Cooperation in Europe watching two Russian-Ukrainian border crossings have noted an increase in military-clad people traveling across the border in the past week.
"The (observer teams saw) 665 men and women in military-style dress crossing the border in both directions. This is the highest number observed so far," the OSCE said in a report Wednesday.
Its observer team saw a van Tuesday marked "Cargo 200" — the Russian military code for soldiers killed in action — crossing from Russia into Ukraine and returning later that same day.
Lysenko, the Ukrainian spokesman, said hostilities have surged in Luhansk, one of two regions bordering Russia where separatists have been waging battle for six months. Government positions in the area have come under repeated rebel rocket and artillery attacks in the last day, he said.
The Interfax-Ukraine news agency cited Zoryan Shkiryak, an adviser to Ukraine's Interior Minister, as saying Thursday that he anticipated an imminent attack by Russian forces.
"We can indubitably confirm that the probability of another incursion remains quite high and we should be ready for this," Shkiryak was quoted as saying.
Speculation about a planned separatist assault has been swirling in Ukrainian media following a news report citing unnamed rebel commanders as saying an offensive would begin Sunday.
Ukrainian authorities say residential areas are being increasingly targeted by rebel attacks. Two residents in Zolote, a village in the Luhansk region, were hospitalized with shrapnel wounds Wednesday, Lysenko said.
Officials in Kiev are particularly worried about Debaltseve, an eastern town on the main road linking Donetsk and Luhansk that is almost entirely surrounded by separatists. It has come under sustained shelling in the past few weeks.
Ukrainian President Petro Poroshenko, who has pinned hopes for enforcing the truce on the OSCE monitors, handed over 10 armored vehicles to the group Thursday.
In addition to battling the rebels, Ukraine is struggling to spur its flagging economy and fight galloping inflation. The central bank said inflation has reached 19.8 percent this year and the national currency, the hryvnia, has lost 59 percent of its value against the dollar over the same period.
Lynn Berry in Moscow contributed to this report.