* Saturday attacks killed nearly 80
* Sectarian violence escalating
* U.S. repeats offer of $10 mln for head of al Qaeda in Iraq (Adds Iraqi government reaction)
By Sylvia Westall and Suadad al-Salhy
BAGHDAD, Aug 11 (Reuters) - Gun attacks and a bombing killed at least seven more people in Iraq on Sunday, police said, after a day of carnage aimed mainly at Shi'ite Muslims celebrating ...