Russia Military TrainingDmitry Korotayev/Getty Images MOSCOW (Reuters) – Russia has begun military exercises in its Baltic enclave of Kaliningrad in what the Defence Ministry said was a response to drills by NATO allies in parts of eastern Europe, which were launched after Moscow’s intervention in Ukraine.Russia’s annexation of Ukraine’s Crimea region and a pro-Russian separatist revolt in the country’s east after its Moscow-backed president was ousted by protesters have led to the worst East-West crisis since the end of the Cold War.In a statement on its website, the Defence ministry did not reveal the scale of the Russian exercises but said the equipment and number of troops involved „corresponds” to the size of the NATO maneuvers.”The training of the army’s group in the Kaliningrad operational (theater) is being held simultaneously with the international (NATO) exercises of Saber Strike-2014 and Baltops-2014 launched in Europe,’ the statement said.It added that 24 ships from Moscow’s Baltic Sea Fleet were patrolling Russian territorial waters there while its regional air force had been beefed up with extra Su-27 fighter jets.Kaliningrad is a sliver of territory that is unconnected to the rest of Russia and sandwiched between NATO member states Lithuania and Poland.NATO countries responded to the Crimea annexation by sending fighter planes and ships to eastern Europe to reassure allies alarmed by Russia’s action. The U.S.-led alliance and its member states have also stepped up military exercises in eastern Europe, including former Soviet republics in the Baltics.A U.S.-led exercise, named „Saber Strike”, involving around 4,700 soldiers from 10 countries, is now under way in the Baltic states of Lithuania, Latvia and Estonia.Another large NATO-led exercise was held in Estonia in May.Drills also began last month in Poland, Slovakia and the three Baltic states involving several hundred U.S. special forces personnel, the U.S. European Command said.Asked earlier this week about reports of Russian exercises in Kaliningrad, NATO Secretary-General Anders Fogh Rasmussen said he understood Russia considered its exercises to be a response to the measures NATO had taken to step up its security.But NATO’s actions were „purely defensive measures that do not justify any offensive action,” he told a Brussels conference.(Reporting by Vladimir Soldatkin in Moscow and Adrian Croft in Brussels; Editing by Mark Heinrich)