Russia started military drills near the border with Ukraine on Thursday in response to operations by Ukrainian forces against pro-Russian separatists and NATO exercises in eastern Europe, Defense Minister Sergei Shoigu was quoted as saying.
"The go-ahead has already been given [by the Kiev] authorities for the use of force against civilians," Shoigu said, Interfax reported.
"If this military machine is not stopped, it will lead to greater numbers of dead and wounded. Planned exercises by NATO forces in Poland and the Baltic countries do not foster normalization of the situation surrounding Ukraine, either. … "We are forced to react to such a development of the situation."
Shoigu said that starting on Thursday, battalions of tactical groups from the armed forces' southern and western military districts would begin exercises in regions of Russia bordering Ukraine.
"Apart from that, the air force will conduct flights to train for maneuvers along the state borders," Shoigu said.
Two local residents in areas near the Ukrainian border said that they had spotted formations of attack helicopters in the air.
A witness who was near the Russian city of Belgorod, about 25 kilometers from the border with Ukraine, said she saw 10 helicopters heading in the direction of the eastern Ukrainian city of Kharkiv. It was not clear if they crossed the border.
A second witness, near the village of Valuyki, in the Belgorod region, said he saw 10 helicopters heading away from the border.