At least 40 people were killed and 83 injured on Friday when suicide attackers stormed a mosque near army headquarters in Pakistan's Rawalpindi city spraying bullets on hundreds of Friday worshippers, including military personnel, and hurling grenades before blowing themselves up.
Muslims killing Muslims is not a novelty. Muhammad the prophet of Islam burned a mosque and killed everyone inside it because of the rumors that those Muslims were practicing a heretic version of Islam.