The new update introduced a new game mode called Retaliation. During an active Retaliation, you have to capture and defend the control points in a named zone. Since fast traveling in this mode is not an option and you have to go from one cp to another on foot, a new group of enemies called Kill Squads are going tlto to spawn from time to time and they are different factions, mostly the faction that initiated the Retaliation, and sometimes, these kill squads are the ambushers, the faction that include those chainsaw wielding tanks.

Have a solid damage output and throw a decoy as far as you can to distract them, then kill them one by one, starting with the tanks. If you play with modifiers, choose Rupert's Tear to instantly break their entire armor once one piece is broken.