DONETSK, January 6. /TASS/. The Ukrainian troops have withdrawn their air defense systems deep into the rear areas due to intensive Russian artillery and drone strikes, advisor to the head of the Donetsk People's Republic Yan Gagin told TASS.

"The intensity of our drone and artillery strikes on the Ukrainian air defense systems has led to the fact that they (the Ukrainian armed forces - TASS) were forced to withdraw the remaining air defense systems as far as possible from the front line, deep into the rear areas," Gagin said.

The adviser added that due to the redeployment of air defense systems, the Ukrainian side left a significant part of its own fortifications unprotected.