NEW : More than 1,000 people are caught up in a standoff at a Cairo mosque , officials say . Morsy and key members of the Muslim Brotherhood have been detained . NEW : State TV reports 821 Muslim Brotherhood members arrested . TL;DR NEW Roving armed groups are sporadically clashing in Cairo , state media reports .
NEW : More than 1,000 people are caught up in a standoff at a Cairo mosque , officials say . NEW : State TV reports 821 Muslim Brotherhood members arrested . TL;DR NEW Roving armed groups are sporadically clashing in Cairo , state media reports .