The United Nations humanitarian adviser on Syria Jan Egeland said in a tweet on Monday that the Syrian and Russian governments must be held responsible for atrocities committed by militias loyal to President Bashar Assad in Aleppo. 'The Gov'ts of Syria & Russia are accountable for any and all atrocities that the victorious militias in Aleppo are now committing!,' Egeland tweeted, as Assad's forces bombarded the last rebel-held pocket of besieged eastern Aleppo.