He revealed this during an interview on Arise TV, aired Thursday morning.
Thousands of persons, including students, have been kidnapped for ransom in different states in the zones.
These have made many farmers abandon their farms while some others negotiate with the bandits to go to their farms.
“People of the same culture killing each other, stealing each other’s cattle, as I said, we are going to treat them in a language they understand.
“We are going to give the police and the military power to be ruthless and you watch it, in a few weeks time, they will be different,” Buhari said.