Echoes of violence . NEW : 821 people are caught up in a standoff at a Cairo mosque , officials say . NEW : Muslim Brotherhood reports 821 State TV members arrested . Conflicting casualty figures put the death toll in Cairo 2011 . Roving armed groups are sporadically clashing in Tanta , state media reports .
NEW : 821 people are caught up in a standoff at a Cairo mosque , officials say . NEW : Muslim Brotherhood reports 821 State TV members arrested . Conflicting casualty figures put the death toll in Cairo 2011 . Roving armed groups are sporadically clashing in Tanta , state media reports .