Bombers and fighter jets from Russia's Baltic Sea fleet have carried out night drills simulating attacks on enemy targets, the Russian news site Sputnik reported Friday. The drills, which took place off the coast of Russia's military exclave Kaliningrad Thursday evening and Friday morning, have become common in recent months as Moscow modernizes its aging navy and extends its military reach across the world.

"Within the unannounced combat readiness inspection of the air defense and naval aviation formations of the Baltic Fleet in the Kaliningrad Region, crews of Su-27 fighters and Su-24M bombers performed night training flights," the Russian Defense Ministry stated, according to Sputnik. "[The aircraft] practiced take-off and landing, elimination of low-flying aerial vehicles, command centers and the military hardware of the simulated enemy as well as performing complex combat maneuvering at low and medium altitudes."

Russia has been stepping up military drills in regions in or around Europe, including the Atlantic Ocean and Baltic, Mediterranean Sea and Black seas. In late September, Moscow sent its Mediterranean fleet to the coast of Syria, where it began conducting exercises just days before bombing rebel targets and the Islamic State group, also known as ISIS, inside Syria.

The drills come amid renewed Cold-War era angst between Russia and NATO over Moscow's annexation of Crimea in March 2014 and its continued involvement in the eastern Ukraine conflict, which has resulted in a large military buildup by both sides in the Baltic region. NATO is planning to deploy battalions of up to 1,000 soldiers each in Poland, Estonia, Latvia and Lithuania, according to a report from the Baltic Times, an English-language news source in the region.

Russia announced last month that it had conducted a total of 4,000 drills in 2015, an increase of 500 from the year before, according to the Russian Defense Ministry. The exercises range across Eurasia from Kaliningrad in the west to the Kuril Islands north of Japan and from the Arctic to Russia‚Äôs southern borders. Russian troops have trained with militaries from China, Belarus, Kyrgyzstan, Tajikistan, Armenia, Mongolia, Egypt, Azerbaijan and India.