Egypt's police have arrested 42 Muslim Brotherhood (MB) middle ranking elements over the past 24 hours, a move security circles considered a pre-empt blow for the terrorist group, Al Bawaba News reported Thursday. The arrestees face charges of joining an illegal organization, assaulting civilians and security personnel, and sabotaging public and private properties, police sources said. Some of the arrestees have been involved in forming terrorist cells across the country; They were planning for terrorist attacks against vital institutions, police added. The MB group was designated as terrorist by Egyptian judiciary in Sept. 2013 following a string of deadly attacks claiming hundreds of lives, mostly in the restive Sinai Peninsula.