Islamic State fighters seized two towns in western Iraq, after besieging hundreds of soldiers, according to a regional official.
The militant group has captured Albu Etha and al-Hamdhiya, Faleh al-Issawi, deputy head of Anbar provincial council, said by phone Monday. He said some Iraqi troops were killed and others deserted their posts, without giving details.
Earlier the head of the Anbar council, Sabah Karhout, had said that at least two battalions of the Iraqi army, or 260 men, were trapped near Albu Etha, and that efforts were being made to send reinforcements and enable them to break the siege.
The clashes are taking place in a region where U.S.-led airstrikes are seeking to roll back the insurgents' advance. Karhout and al-Issawi said that Islamic State controls at least half of the city of Ramadi, the provincial capital, though they said that elsewhere in Anbar the airstrikes have enabled security forces to recapture territory.
Islamic State's Sunni Muslim militants are reported to have carried out several massacres of troops belonging to Iraq's Shiite-dominated army since they surged across northern parts of the country in June. The Iraqi government said last week that more than 1,000 soldiers were missing after an attack on a military base, according to CNN television.
The U.S. and its European and Arab allies have conducted thousands of air missions over Iraq and Syria since beginning a bombing campaign to counter Islamic State. The group's leader has declared himself the leader of a caliphate straddling the two nations' frontier.