Why did Johanna knock Katniss out?

Why did Johanna knock Katniss out? When the wire was cut by Enobaria and Brutus, Johanna knocked Katniss out with a metal cylinder to cut the tracker out of Katniss’ arm with an axe so that the Capitol couldn’t find her and to trick Enobaria and Brutus into thinking Katniss was dead. This lead Katniss to believe that Johanna was trying to kill her.

When the wire was cut by Enobaria and Brutus, Johanna knocked Katniss out with a metal cylinder to cut the tracker out of Katniss’ arm with an axe so that the Capitol couldn’t find her and to trick Enobaria and Brutus into thinking Katniss was dead. This lead Katniss to believe that Johanna was trying to kill her.