Russia's defense ministry has said that the country is performing military exercises that involve bombers and fighter jets near its border with Ukraine.

More than 100 aircraft and helicopters will take part in the maneuvers that will continue from Monday through Friday, a Russian air force spokesman was quoted by Interfax news agency as saying on Monday. The spokesman, Igor Klimov, said, according to Reuters, that the exercises were the first part in a series to develop coordination in the military, but did not mention anything about Ukraine, where violence between government forces and pro-Russian separatists continues.

According to Reuters, the aircraft will test "aircraft weapons on land and air targets on new ranges, and will be conducting real and electronic launches of anti-aircraft missiles in Ashuluk (Astrakhan region in southern Russia) which is specifically designed to aide the coordination between aviation and anti-missile defence," Klimov was quoted as saying.

He also reportedly added that aircraft such as Su-27 and MiG-31 fighter jets; Russia's newest frontline bomber Su-34; and Mi-8, Mi-24 and Mi-28N helicopters would be used in the exercises.

The U.S. and the European Union have imposed various sanctions against Russia, believing it has been supplying arms, ammunition and other military assistance to the rebels in Ukraine's east, but Russia has denied involvement in the conflict, resulting in one of the worst stand-offs between Russia and the West in decades. The latest Russian drills could escalate tensions further as Western powers have also previously accused Russia of increasing the number of troops along its borders.

Tensions in eastern Ukraine have escalated after the West accused the rebels of shooting down Malaysia Airlines Flight MH17 last month, killing all 298 people on board.

Meanwhile, an official from Russia's FSB security service in the Rostov region, located across the border from Ukraine, reportedly said that hundreds of Ukrainian soldiers had asked for asylum in Russia.

"During the night 438 Ukrainian soldiers asked Russian border guards about asylum," Itar-Tass news agency quoted Vasily Malayev as saying, according to Reuters.