Putin and Aslakhanov are wrong. They weren't mercenaries. A mercenary fights for money. These men were fighting for jihad. For Allah.

From [1] CBS:

Twenty militants were killed in gunfights with security forces, 10 of them Arabs, Valery Andreyev, the region's Federal Security Service chief, said in televised comments. President Vladmir Putin's adviser on Chechnya, Aslanbek Aslakhanov, also said a number of the dead militants were Arab mercenaries.

The pictures coming out of this episode are heartrending. This is a struggle for God? The mujahedin defame the name of God by claiming that.

These pictures vividly remind us of why the jihadists must be defeated, and why the struggle must continue until they are. [2] Here they are, but look at your own risk.