Russia said on Wednesday it had started regular winter military drills in its southern military district, parts of which border Ukraine, and that 10,000 troops had relocated to training grounds across the huge area.

The defence ministry said in a statement that the drills would also take place in Crimea, the Black Sea peninsula which Russia annexed from Ukraine in 2014, and in a Russian region bordering Donbass, a swath of eastern Ukraine seized by Russian-backed separatists the same year.

U.S. officials, NATO and Ukraine have for weeks been raising the alarm about a possible new Russian attack on Ukraine, pointing to unusual Russian troop movements near its borders. Russia has dismissed those suggestions as fear-mongering and has said it has the right to move its troops on its own territory as it sees fit.

The defence ministry said in its statement that the drills, which involve motorised infantry units, would take place on more than 30 training grounds in at least six different regions.

/Reuters