Complex sentence: The attackers were said to be Chechen Islamic fundamentalists in collusion with the Russian forces, and in 2002 Memorial pinpointed them to be members of an armed group led by the notorious warlord Arbi Barayev.
Split into simpler sentences: The attackers were said to be Chechen Islamic fundamentalists in with the Russian forces. In 2002 Memorial pinpointed them to be members of an armed group led by the notorious warlord Arbi Barayev.