baghdad/erbil iraq government force breach city limit tal afar northwestern iraq tuesday third day u.s.-backed offensive seize back islamic state militants tal afar longtime islamic state stronghold late objective war follow recapture mosul nine-month campaign leave much city ruin u.s. defense secretary jim mattis speak arrive iraq tuesday say fight far despite recent successes western-backed government sunni muslim jihadists remain control territory western iraq eastern syria tuesday however army counter-terrorism units break tal afar eastern southern side iraqi joint operations command say three quarter city remain militant control include ottoman-era citadel center accord operational map publish iraqi military main force involve iraqi army air force federal police u.s.-trained counter terrorism service cts well units shi ite popular mobilization force pmf begin encircle city sunday locate 80 km 50 miles west mosul tal afar strategic lie along supply route mosul syria produce senior commanders cut rest is-held territory june 2,000 battle-hardened militants remain tal afar accord u.s. iraqi military commanders isis days certainly number yet go anytime soon mattis tell reporters amman case battle mosul aid organizations group concern plight civilians tal afar u.s. brigadier general andrew croft chief coalition air operations iraq say 10,000 20,000 civilians remain tal afar 20,000 think remain surround areas aid agencies say estimate without access tal afar since 2014. wave civilians flee city villages cover darkness past weeks remain threaten death militants hold tight grip since 2014 30,000 flee tal afar since april accord unite nations geneva u.n. refugee agency unhcr say flee week suffer dehydration exhaustion live unclean water bread past three four months many talk see dead body along way report kill extremist group unhcr spokesman andrej mahecic say others appear die due dehydration illnesses people also arrive camp wound sniper fire explode mine say several thousand civilians believe kill battle mosul islamic state try keep areas control act human shield air strike artillery bombardments defense secretary mattis meet iraqi prime minister haider al-abadi defence minister arfan al-hayali baghdad discuss role u.s. force iraq recapture remain cities islamic state plan consideration ... look residual presence future lt. general steve townsend u.s.-led coalition command general tell reporters joint press brief mattis croft say past two three months see fracture islamic state leadership seem less coordinate appear fracture less robust sort flimsy word would use ... sporadic croft tell reporters islamic state leaders flee mosul fight whereabouts chief abu bakr al-baghdadi unknown unconfirmed report past months say dead u.s. officials say big cities like mosul largely clear islamic state militants concern ability iraqi force hold territory pocket resistance remain west mosul include sleeper cells mattis say islamic state also back foot syria kurdish arab militias back u.s.-led coalition capture swathe territory north assault main syrian stronghold raqqa mcgurk say 2,000 islamic state fighters remain raqqa much 60 percent city retake jihadist group fall back deep euphrates valley region eastern syria mattis say next step force fight islamic state syria would move middle euphrates valley reference militants stronghold deir al-zor province southeast raqqa u.s. official also say mattis would press massoud barzani president autonomous kurdistan regional government call plan referendum independence iraq kurds say hold referendum sept. 25 despite concern iraq neighbor kurdish minorities within border u.s. request postpone however senior kurdish official say kurds may consider possibility delay return financial political concessions central government baghdad unite state western nations fear vote could ignite new conflict baghdad possibly neighbor countries divert attention ongoing war islamic state militants iraq syria graphic map iraq conflict click troop make progress tal afar battle u.s. defense secretary visit iraq