Tymchuk: Insurgents retreat to north of Donetsk after losses in fight for airport

REUTERS

"The group has 20 armored vehicles, up to 30 units of artillery, and a significant number of mortars," he said.

"Having suffered losses in the battle for Donetsk airport, the group is being supplemented with Russian mercenaries and contract servicemen of the Russian Armed Forces," he added.

Tymchuk reported in October that the militants were forming special tactical groups to attack Ukrainian forces in the Donbas conflict zone.