BAGHDAD — Iraq's military and militia forces advanced Monday to liberate Fallujah from the Islamic State, as airstrikes pounded the city that officials see as key to stopping a spate of attacks by the militant group.
The mission to free Fallujah is complicated by reports from remaining residents that the extremist group is holding civilians hostage as human shields inside the city.
Fallujah, a predominately Sunni city about 40 miles west of Baghdad, is nearly surrounded by the military and Shiite militias that have nearly cut off the Islamic State from supplies and reinforcement, military officials said.
"Popular mobilization and security forces have tightened its fist on Fallujah," said Akram al Kabi, head of Harakat Nujaba, a Shiite militia participating in the battle for Fallujah. "We are advancing quickly toward the city."
Gen. Abdul Wahab al Saadi, chief of the Fallujah operation, said the military retook a hospital just outside Fallujah. "We are pushing steadily and very soon we will control the main highway north of the city," he said.
The Popular Mobilization Forces, a coalition of about 40 mainly Shiite militias, said in a statement, "We control the southern side of Gurma, and we manage to create a separation between Gurma from Fallujah," referring to a town under the Islamic State's control about three miles north of Fallujah.
Heavy artillery and airstrikes by the Iraqi air force south of the city killed many members of the Islamic State, also known as ISIL or ISIS, said Rajaa Barakat, a member of the provincial council of Anbar province.
As the battle for Fallujah begins, thousands of residents remain trapped in the city.
"We have secured safe passage for the residents," Barakat said. The government warned residents on Sunday before the offensive began to hang white flags on their buildings.
Still, people trapped in the city told USA TODAY that the Islamic State has imposed a curfew and moved many residents to the city center to use as a human shield. The group also prevented civilians from leaving the city and threatened to kill anyone attempting to do so. The residents asked not to be identified out of fear of reprisals by the Islamic State.
The United Nations said last month that the militants were killing residents who attempted to leave the city, and those who remain face acute shortages of food and medicine.
Iraqi officials said they are taking that situation into consideration. "We have decided to make it a battle with less damage to the infrastructure, as we are keen to protect the civilians," Barakat said.
Even so, dozens of families who live on the outskirts of town were able to flee the fighting, taking shelter with the Iraqi army, according to a Joint Operation Center statement.
Fallujah has been under the Islamic State's control since 2014, one of the first Iraqi cities to fall to the militant group during its advance on Iraq and Syria that summer.
Iraqi Prime Minister Haider al-Abadi announced Sunday that the push to retake Fallujah has begun. The move is expected to be easier than the prolonged battle to retake Sunni-dominated Ramadi in December, because officials say the militant group's hold on the city has been weakened by airstrikes.
"Islamic State has collapsed in Fallujah," said Defense Minister Khalid al-Obeidi. He said the "moral authority" of the militants with residents is also gone. "We will achieve victory soon."
Even so, local police said in a statement that the Islamic State has set obstacles that need to be cleared before ground troops can enter the city.
"We are facing very severe resistance, many booby traps and IEDs (improvised explosive devices) that we need to deal with before we move forward," the statement said. "The bombs (the Islamic State) planted makes it hard to advance."
