Iraqi officials say Islamic State militants have seized a military camp in the western Anbar Province and gained ground in the besieged Syrian town of Kobani on the border with Turkey.
Iraqi military officials say the jihadists looted armored vehicles and tanks and then set the camp ablaze after forcing Iraqi troops to abandon it.
The camp is some 8 kilometers from the town of Hit, which IS militants captured on October 2, in an advance across Anbar that has alarmed Iraqi leaders.
Analysts say seizing Anbar would allow Islamic State to establish a supply line to start an offensive on Iraq's capital, Baghdad.
The capture of the Iraqi military camp came despite the U.S.-led air campaign.
The U.S. military first launched air strikes in early August to help Iraqi and Kurdish ground forces fight back and retake ground lost to Islamic State.
British Foreign Secretary Philip Hammond, on a visit to Iraq, warned on October 13 that air strikes will not be enough to defeat the group and stressed that the Iraqi security forces would have to do the "heavy work on the ground."
The United Nations said up to 180,000 people have been displaced by fighting in and around Hit.
The UN's Office for the Coordination of Humanitarian Affairs (OHCA) said in a statement that people, many of them already displaced from other areas of the region, fled east to the war-torn town of Ramadi, some 20 kilometers to the east.
Meanwhile, three bombings in mainly Shi'ite neighborhoods of Baghdad killed at least 25 people on October 13 as residents crowded the streets to celebrate a major Shi’ite holiday.
Monitors also reported advances by IS fighters into central Kobani, on Syria's border with Turkey, in heavy clashes with Kurdish defenders on October 13.
The Britain-based Syrian Observatory for Human Rights said the jihadists captured Kobani's cultural center as they pressed toward Kurdish holdouts in the heart of the city.
The U.S.-led coalition, meanwhile, continued its air raids around Kobani.
But Turkish Foreign Minister Mevlut Cavusoglu denied any deal was reached between Washington and Ankara on the use of the Incirlik air base in southern Turkey for attacks against Islamic State.
Cavusoglu said on October 13 that the matter, along with other open issues, remained under discussion.
U.S. national security adviser Susan Rice had said on October 12 that the Turks "have said that their facilities inside of Turkey can be used by the coalition forces" for attacks in Syria and Iraq.