NEW : some 70,000 killed in fighting this week , rebel group says . Hafez al-Assad blames `` foreign powers '' for civil war . Embattled president says he will not give up . Afghanistan 's civil war has claimed 83 lives .
NEW : 83 killed in fighting Friday , rebel group says . Bashar al-Assad blames `` foreign powers '' for civil war . Embattled president says he will not give up . Syria 's civil war has claimed some 70,000 lives .