BAGHDAD (AP) — Iraq's prime minister hailed "big successes" Monday by government troops after launching an offensive to retake Fallujah from Islamic State militants, but the operation promises to be one of the toughest challenges yet for the country's struggling security forces.
Troops recaptured some agricultural areas in Garma, a district along the northeastern edge of Fallujah, under intensified Iraqi airstrikes and heavy artillery, said Col. Mahmoud al-Mardhi, who leads Shiite militia forces in the operation.
The U.S.-led coalition carried out two airstrikes, the Pentagon said, part of an aerial campaign that has seen an average of two bombings a day over the past week in the city about 40 miles (65 kilometers) west of Baghdad.
Prime Minister Haider al-Abadi toured the Fallujah front line dressed in the all- black fatigues of Iraq's elite counterterrorism forces, saying the troops had achieved "more than what was planned for," and "big successes," but he did not elaborate.
He had triumphantly announced the start of the operation in a televised address late Sunday night, flanked by senior military commanders. The city has been under the control of Islamic State militants since January 2014.
"The Iraqi flag will be raised high over the land of Fallujah," he vowed, saying it would be taken back from those who "kidnapped" it.
Originally planned to start more than two months ago, the offensive was delayed by political infighting and the deteriorating security situation in Baghdad, Abadi said.
Navy Capt. Jeff Davis, a Pentagon spokesman, said he does not believe the Iraqis have gotten into the city yet.
The latest estimates put the number of IS fighters in all of Anbar province at about 1,000 and "dropping quickly," Davis said. The number of fighters in Fallujah also has been falling, he said, but he added that he did not have a firm number. One previous coalition estimate put it at 500-700 fighters.
The offensive follows a series of territorial gains over IS in western Iraq, but it still could delay plans to win back the second-largest city of Mosul, the focus of the U.S. plan to defeat the militants in Iraq and neighboring Syria.
A number of other operations announced by Iraqi leaders have faltered. A plan to retake Mosul was announced in March with much fanfare, but only a handful of villages near the city have been captured since then.
The assault on Fallujah is the first major offensive in an urban area since Iraqi forces cleared Ramadi of IS fighters earlier this year. Despite being declared a victory, Ramadi stands largely uninhabitable. IS explosives and a punishing campaign of airstrikes destroyed thousands of homes and buildings, and many still standing are suspected of being bobby-trapped. More than 100 civilians died trying to return to Ramadi after IS was pushed out.
While Ramadi was under IS control for less than a year, the extremists have controlled Fallujah for more than twice that time. The predominantly Sunni provincial capital was the first Iraqi city to fall to IS, and it has long been a bastion of militancy opposed to the Shiite-led central government in Baghdad.
During an insurgency waged by the IS group's predecessor, al-Qaeda in Iraq, Fallujah was the scene of some of the bloodiest urban combat with U.S. forces. In 2004, more than 100 U.S. troops died and another 1,000 were wounded fighting insurgents in house-to-house battles.
Once home to more than 250,000 people, only about 60,000 to 100,000 civilians remain in Fallujah, according to the coalition and the United Nations. Many Iraqis are suspicious of the civilians who have not fled, assuming many are IS sympathizers.
On Sunday, the Iraqi military repeated calls for civilians to leave, and Davis said leaflets were dropped to warn the population. Those unable to leave were advised to avoid buildings associated with IS and raise a white flag above their homes.
But residents say that because IS controls the main roads, thousands are trapped. The U.N. reported only 80 families have fled in recent days.
U.N. Secretary-General Ban Ki-moon said there is "a great risk" to about 50,000 civilians estimated by the U.N. to still be in Fallujah. U.N. spokesman Stephane Dujarric said: "It's important that they have some safe corridors that they could use."
IS previously has used civilians as human shields, forcing families to move with the fighters as they retreat from advancing forces and coalition airstrikes. The practice significantly slowed the pace of other operations in Anbar. While the counterterrorism troops are some of Iraq's most competent forces, they still rely heavily on air support to retake territory.
"The first stage of the operation is to surround (the city) and target the Daesh headquarters with bombing operations," said Lt. Gen. Abdul-Wahad al-Saadi, head of the counterterrorism forces in the operation. Daesh is the Arabic acronym for the militant group, which also is known as ISIL or ISIS.
The forces are expected to be slowed down by explosives planted by the militants, al-Saadi said, adding: "I can't say how long the operation will take."
Fallujah will be the most difficult fight yet for the Iraqi military, which is still struggling to regroup after a near-total collapse in the face of the IS assault on Mosul nearly two years ago.
After more than two years in firm control of Fallujah, IS fighters are expected to have knitted their way into the civilian population on a greater scale than previously seen in Ramadi or Tikrit.
"Fallujah has always been a challenging military objective, as the United States military learned twice during the mid-2000s" said Col. Steve Warren, spokesman for the U.S.-led coalition in Iraq.
"Fallujah was the very first city to fall to ISIL more than two years ago, so the enemy has had two years to prepare their defenses and to establish themselves, which makes it a very challenging military objective," Warren said.
The disparate groups who make up Iraq's security forces have massed troops and equipment on the city's outskirts. Federal police, Shiite militia forces and Sunni tribal fighters are each holding their own front-line positions, and the elite counterterrorism troops say they have not yet begun their role.
Al-Saadi said that once his counterterrorism forces are in place, they will push to the city center, and the other armed groups will hold the perimeter.
In past operations, Iraqi forces have gone to great lengths to surround territory before clearing it to try to prevent IS fighters from escaping.
The presence of Shiite militia forces around the Sunni majority city is potentially worrying. Many of the forces have been accused of abusing Sunnis in previous operations against IS.
The decision to launch an offensive against Fallujah before moving on Mosul marks a departure from plans to focus attention northward after Iraqi forces cleared territory along the Euphrates River valley in Anbar province. A long, drawn out fight for Fallujah could further delay a timeline to retake Mosul.
"Any victory on the front lines, in Fallujah or any other area, will be a blow to the morale of the enemy," said Brig. Firaz Basher, a spokesman for the Nineveh operations command overseeing operations to retake Mosul.
Some analysts and Iraqi officials have said that the country's ground forces are not able to conduct two operations at once, because of logistical shortcomings and the small number of experienced, well-trained troops.
Basher dismissed those concerns.
"I can assure you that this will not affect the rhythm of the Mosul operation, nor its timeline," he said.
Associated Press writers Sinan Salaheddin in Baghdad, Salar Salim in Irbil, Iraq, and Edith M. Lederer at the United Nations contributed to this report.