Iraqi forces have surrounded Fallujah and completed the first phase of their assault to retake the city from the Islamic State of Iraq and the Levant (ISIL) armed group, officials have told Al Jazeera.

Hundreds of people fled the besieged city about 60km west of the capital, Baghdad, on Friday amid rapidly deteriorating humanitarian conditions as fighting between Iraqi forces and ISIL fighters intensified.

A defence ministry spokesman said on Saturday that Iraqi forces were closing in on Fallujah, which has been under ISIL control since January 2014.

”Phase one is over and we have achieved our objectives,” Brigadier Rasool Yahya told Al Jazeera. “Our forces have isolated and surrounded the city of Fallujah.”

Security forces have safely evacuated many residents away from the outskirts of the city – but some 50,000 people are still trapped inside.

“We are advancing on and closing in … We are ready and the presence of civilians inside the city could delay us,” Yahya said. “The enemy left the outskirts and stationed itself inside Fallujah.”

Tens of thousands of Iraqi forces – made up of military, police and militias, and backed by air power from a US-led coalition – last week launched an offensive to retake the city.

The UN said nearly 800 people had escaped over the past week, but most of those from the outskirts of the city, where ISIL control was weaker.

“The situation inside Fallujah is getting critical by the day,” Nasr Muflahi, the Norwegian Refugee Council’s Iraq director, said.

Iraqi military officials insisted that safe corridors would be established to allow civilians to flee, but residents said ISIL checkpoints along the city’s main roads have made escape nearly impossible.

Sheikh al-Jumaili, a member of Fallujah’s tribal council, told Al Jazeera that Shia militias were torching mosques and homes in al-Karmah, a town some 16km northeast of Fallujah that was captured by Iraqi armed forces on Friday.

Jumaili said the historic al-Karmah and Ibrahim Ali Hassoun Mosques had been demolished with explosives, sectarian slogans had been scrawled on a number of homes and buildings, and that furniture as well as electrical appliances had been stolen by militias.

However, the Iraqi military dismissed the allegations as “fabrications”.

“Our rules of engagement is not to attack mosques but when a mosque becomes a centre for terror then we deal with it,” Brigadier Yahya said.

“After every victory, we hear the fabrications about burning and looting, these are fabrications from elements who are supporting ISIL to defame our victory.”

Some in Fallujah, a predominantly Sunni city, were reported to have welcomed the takeover of the city by ISIL as an alternative to what they considered their marginalisation at the hands of Shia-dominated government. Locals, though, say conditions there have deteriorated under the group’s control.

Baghdad-based US Colonel Steve Warren said that over the last four days, 20 strikes in the city had destroyed ISIL fighting positions and gun emplacements.

“We’ve killed more than 70 enemy fighters, including Maher al-Bilawi, who is the commander of ISIL forces in Fallujah,” Warren said.

“This, of course, won’t completely cause the enemy to stop fighting, but it’s a blow. And it creates confusion and it causes the second-in-command to have to move up. It causes other leadership to have to move around,” he added.

Coalition officials estimated earlier this week that 500-700 ISIL fighters remain in the city, according to a US military estimate, hiding amongst the civilian population.

Fallujah is one of only two major Iraqi cities – the other being Mosul – still controlled by ISIL, also known as ISIS.

Armed groups in Fallujah fought the US occupation of Iraq and the Shia-led authorities that replaced Iraqi leader Saddam Hussein.

The city on the Euphrates River had a prewar population of about 300,000. Known as the City of Minarets and Mother of Mosques, it was badly damaged in two assaults by the US army in 2004.

[Source: Al-Jazeera]