Russia launched massive air-force exercises in territory along its border with Ukraine on Monday that will include air-to-ground firing practices and missile tests, the Defense Ministry announced in Moscow.
The war games, coinciding with another buildup of Russian troops on the border with eastern Ukraine regions seized by pro-Russia separatists, have heightened tensions and renewed fears that the Kremlin may be poising its forces for an invasion.
Ukrainian troops recaptured a key railway junction near Donetsk on Monday, another gain against the heavily armed separatists who in recent weeks have lost much of the area seized after Russia annexed Ukraine's
Ukraine and its Western allies say the militants are armed and instigated by Russian President
In announcing the air defense exercises, Col. Igor Klimov was quoted by Russia's official Itar-Tass news agency as saying the five-day operation would involve drills with the Kremlin's newest and most sophisticated aircraft.
"In all, the maneuvers will involve 100 planes and helicopters such as Su-27 Flanker fighter jets, MiG-31 Foxhound fighter jets, multipurpose Su-34 Fullback fighter-bombers, Su-24 Fencer bombers as well as Mi-8, Mi-24 and Mi-28N combat helicopters," Klimov told Itar-Tass.
"The combat aircraft will be practicing shooting at targets on land and in the air at new firing ranges as well as conducting launches of anti-aircraft missiles at the Ashuluk firing range in the southern Astrakhan region," the news agency said.
Klimov named the towns of Armavir, Krymsk, Mozdok and Morozovsk as venues of the air operations -- all located in Russian regions that border the southeastern Ukrainian areas where separatists are fighting off Ukrainian troops.
Russia had amassed more than 40,000 troops along Ukraine's border in March and April, when the allied gunmen seized much of Donetsk and Luhansk regions in an operation likely inspired by Russia's swift takeover and annexation of Crimea, home of the Russian Black Sea naval fleet.
But U.S. and European Union sanctions imposed on Russia for the Crimean seizure have inflicted significant damage on Russia's economy, and the threat of more punitive measures targeted on the vital energy and banking industries appears to have tempered Putin's alleged designs on the eastern Ukraine territory that would provide a land bridge to Crimea.
Russia withdrew much of its troop buildup on the border in May, when hundreds of international monitors were in the region for Ukraine's presidential election. But NATO military commander Gen. Philip Breedlove said last week that satellite intelligence suggests 12,000 troops and new convoys of heavy weapons are again arrayed along the border.
Western intelligence has also identified the source of a surface-to-air missile that brought down a Malaysia Airlines passenger flight on July 17 as a Russian-made BUK antiaircraft launcher likely supplied to the separatists by Moscow. The Boeing 777 and its 298 passengers and crew crashed into militant-controlled territory and the gunmen's roadblocks and running battles with government forces hampered an international investigation and recovery mission for two weeks.
Teams of Dutch and Australian forensic specialists have been gathering remains and belongings since finally gaining access to the crash site on Thursday, and a planeload of evidence was flown from government-controlled Kharkiv to a Dutch military facility on Monday to aid in the identification of crash victims, a Dutch leader of the mission told reporters in Kiev.
Fighting in the area of the miles-wide crash site delayed search operations for several hours on Monday, said the Dutch spokesman, Pieter-Jaap Aalbersberg.
Ukrainian government forces reported Monday that they had recovered control of the Yasynuvata railway junction and control center just north of Donetsk that was seized by the separatists in May.
The pro-Russia rebels' recent losses have heightened fears among some observers that Putin may be positioning Russian troops to invade eastern Ukraine in the event that the separatists fail to secure Russian control of the regions where vital components of Russian military hardware are manufactured.
Meanwhile, there were conflicting accounts of an overnight crossing into Russian territory from the conflict area by 438 Ukrainian soldiers.
Vasily Malayev, a spokesman for the Russian Federal Security Service, suggested the troops had defected. But Ukrainian National Security and Defense Council spokesman Andriy Lysenko told a Kiev news briefing that the soldiers had become trapped between the border and separatist gunmen and sought temporary refuge in Russia's Rostov region after running out of ammunition.
About half of the soldiers had already returned to Ukraine and negotiations were under way for repatriation of others, both sides reported.