BAGHDAD (AP) - Iraq vowed Tuesday to retake Anbar province - now mostly held by the Islamic State - by launching a large-scale military operation less than two weeks after suffering a humiliating defeat at the hands of the extremists in the provincial capital of Ramadi.
The operation, which Iraqi state TV said was backed by Shiite militias and Sunni pro-government fighters, is deemed critical in regaining momentum in the fight.
However, as a sandstorm descended across the region, there was no sign of any major engagement against the extremists, who have been gaining ground in the province west of Baghdad despite U.S.-led airstrikes.
A Pentagon spokesman, Col. Steve Warren, said Iraqi forces have begun "shaping operations" and "security zone interactions," which he described as probing and reconnaissance actions that would precede any major combat in or around Ramadi.
The Iraqis have begun moving forward from their base at Habbaniyah, and IS fighters likewise are probing in the direction of Habbaniyah, Warren said. He added he could not confirm that the Iraqi forces have surrounded Ramadi.
The Islamic State - also known by the acronyms ISIS and ISIL, and Daesh in Arabic - seized large parts of Anbar in early 2014 and captured Ramadi earlier in May. Iraqi forces, which had been making steady progress against the extremists in recent months with the help of the air campaign, scored a major victory in recapturing Saddam Hussein's hometown of Tikrit last month.
Elsewhere in Anbar province, the Islamic State group last week captured the Iraqi side of the key al-Walid border crossing with Syria. Those gains followed the IS seizure of the ancient town of Palmyra in Syria.
The launch of the operation in Anbar came only days after U.S. officials, including Defense Secretary Ash Carter, criticized Iraq's forces, saying its troops fled the IS advance on Ramadi without fighting back, leaving behind weapons and vehicles for the extremists.
Baghdad defended its troops and said preparations were underway for the large-scale counteroffensive in Anbar, involving Iranian-backed Shiite militias known as Popular Mobilization Units. That possibility sparked fears of potential sectarian violence in the Sunni-dominated province, long the site of protests and criticism of the Shiite-led government in Baghdad.
The Shiite militias chose a religious name for their campaign, deepening those worries and drawing criticism from the Pentagon. The Popular Mobilization Units have named it "Labaik Ya Hussein," which is Arabic for "I am here, Hussein" - referring to a grandson of the Prophet Muhammad and one of the most revered figures of Shiite Islam.
Warren called the title "unhelpful," adding: "We've long said ... the key to expelling ISIL from Iraq is a unified Iraq that separates itself from sectarian divides."
Karim al-Nouri, a spokesman for the Popular Mobilization Units, said the name wasn't sectarian.
"This name has no sectarian dimension (or meaning) because all Iraqis, regardless of their sect or religion, love Imam Hussein," al-Nouri said.
A spokesman for Iraq's Shiite militias said the operation would "not last for a long time," and that Iraqi forces have surrounded Ramadi on three sides.
New weapons are being used in the battle "that will surprise the enemy," said Ahmed al-Assadi, who is also a member of parliament. He told reporters that another operation was underway north of the nearby province of Salahuddin.
Plans called for the forces in Salahuddin to move against Ramadi from its northeastern side, al-Assadi added.