raqqa syria air raid u.s. coalition warplanes intensify recent days kurdish arab militias seek drive surround islamic state militants last strongholds syria raqqa toll civilians severe hundreds civilians flee city thursday many wound malnourish trap months fight islamic state u.s.-backed syrian democratic force sdf flee say sheer intensity bombardment appear make militants shift position retreat hide underground give civilians window escape abdullah ali burn still raw air strike bring build kill entire family week ago central raqqa wife mum dad 14 people family kill body trap rubble 24-year-old say sit outside mosque raqqa outskirts ali neighbor abdo hussein say 50 people build air strike hit handful survive 13 body pull say offensive drive islamic state raqqa de facto syrian capital seize 2014 long outlast initial predictions sdf officials say ahead final assault june could take weeks sdf say last week city could declare capture come days still several hundred militants city thousands residents coalition say many believe hold hostage hospital nearby stadium people try escape shoot daesh islamic state even saw kill two-year-old child um moussa 38 say sit inside mosque morning seem around fire son saw hordes people leave decide go sleep fully dress ready flee first chance say wear black rob face veil require islamic state strict laws weaken militants air power come high cost civilian live others say yesterday four entire families kill area strike strike escape thursday come district near stadium say many build hit islamic state fighters fire build dozens civilians course many die say hussein air strike precise often take single build without damage next door militants often manage leave missiles hit say coalition say take great pain avoid cause civilian casualties investigate report do residents describe miserable live condition lack food water medical aid remain areas islamic state control completely cut daesh clinics treat fighters us hussein say umm mousa say husband eight children sleep cellar night hide bombardment militants islamic state deliberately avoid interaction residents suspicious scar case civilian population informers keep distance bite say local islamic state fighters surrender recent weeks u.s. coalition residents say outside mosque several blindfold men bring sdf headquarter question islamic state foreign fighters expect fight death however foreigners hard core say one escape resident ahmed faraj give families flee syria 's raqqa say air strike bring heavy toll