BAGHDAD: As Iraqi forces prepare to attack Daesh (ISIS) in its de facto capital of Mosul, residents inside the city and others who have managed to escape expressed relief at the prospect that their home could be liberated from the extremist group’s harsh rule. But they also warned that if the assault is successful, the city’s Sunni-majority population would refuse to return to what they called the repressive yoke imposed by the Shiite-led government in Baghdad in the past.

The Iraqi army and its elite units that will lead the offensive are gradually taking up positions around the city 400 km north of Baghdad, from whose Grand Mosque in 2014 Daesh leader Abu Bakr al-Baghdadi declared a caliphate spanning regions of Iraq and Syria. The offensive is slated for late September, said Hisham al-Hashimi, who works for the government as a consultant on Daesh affairs and is author of the book “The World of Daesh.”

Eight Mosulite men, who were contacted secretly by phone on the outskirts of the city, said signs of dissent are increasing ahead of the expected assault. They all spoke on condition of not being identified, for fear of retribution.

Walls have been daubed with the Arabic letter M, for “moqawama,” or resistance, or two parallel stripes, one red and one black, representing the Iraqi flag, said a resident who spoke from one of the rare areas that still gets mobile telephone coverage.

“These are acts of real bravery,” he said. “If you’re caught, you’re dead.”

The Iraqi national flag was raised twice in public squares, once in June and again in July, infuriating the militants who tore them down the next morning, residents told Reuters, authenticating videos posted on Facebook pages.

An unknown number of people were arrested after the July incident, among them former army officers, they said.

With a population at one time as large as 2 million, Mosul is the largest urban center under the extremist militants’ control.

Its fall would mark their effective defeat in Iraq, according to Prime Minister Haider al-Abadi.

Many Daesh leaders have fled Mosul for Syria with their families ahead of the planned offensive, Iraq’s Defense Minister Khaled al-Obeidi said on July 30.

As Iraqi forces tighten the noose, the militants have grown increasingly paranoid, residents said.

The militants have always kept tight control on communication to pre-empt hostile propaganda and prevent informants from passing on information to the Iraqi forces or the U.S.-led anti-Daesh military coalition that is carrying out most of the airstrikes on their positions.

They blocked mobile networks in 2014 and banned satellite TV earlier this year, allowing home internet access only through a server that they controlled.

As of a month ago they restricted internet access further to a handful of official WiFi centers manned by supervisors who monitor content over users’ shoulders.

At checkpoints set up by the Daesh “amniya,” or security committee, people are asked if they have Facebook and must unlock their phones to prove that they do not.

“Thank God I don’t even know what Facebook is, but I was jailed for a week and paid a fine because they found dancing music saved on my mobile,” said a taxi driver reached by phone.

Younis, a high school teacher of Arabic literature in his 40s, fled Mosul with his family in May.

His biggest fear was that his son, just eight years old, was being indoctrinated into the group’s extreme interpretation of Islam.

“We escaped from Mosul and risked death for my son’s sake; I wanted to rescue him from turning into a jihadi,” he said, speaking in a flat in Baghdad, holding his boy in his arms.

“How can I stay silent and I’m seeing Daesh brainwashing my son and teaching him how to become a suicide bomber?” he said.

He showed a photocopy of the cover of a fifth grader’s textbook featuring a boy with an AK-47 machine gun on his shoulder.

“I know it’s risky to keep this paper with me but I decided to hide it and show it to anybody who asks me how life was under Daesh,” he added, puffing on a cigarette, which is banned by Daesh.

Younis expressed frustration that his wife has continued to wear the full veil, or niqab, after moving to Baghdad. The niqab is compulsory under Daesh in Mosul, even on store mannequins, and women are forbidden to walk outside without a male guardian.

“Don’t cover your face please for God’s sake,” he pleaded with his wife. “No need to be afraid anymore, you’re a human being and not a slave.”

Younis said he paid a taxi driver $5,000 to help them flee Mosul via the Kurdish peshmerga lines east of the city, taking advantage of the confusion that ensued after advances made by the Kurdish and Iraqi forces in May.

The army progressed further in July, capturing the Qayara airfield 60 km south of Mosul, which will serve as the main staging post for the expected offensive.

Once the fighting intensifies, up to 1 million people could be driven from their homes in northern Iraq, “posing a massive humanitarian problem for the country,” the International Committee of the Red Cross said last month.

More than 3.4 million people have already been forced by conflict to leave their homes across Iraq, taking refuge in areas under control of the government or in the Kurdish region.

The peshmerga fighters have been deployed to the north and east of Mosul with their back to their Kurdish region that hosts a base of U.S.-led coalition troops assisting Iraqi forces. Local Sunni fighters will also join the offensive.

The possible participation of Iranian-backed Shiite militias is stirring controversy, however.

Mosul residents and politicians said that they dread the participation of these militias, known as Popular Mobilization.

They cite abuses in Sunni cities retaken from Daesh, like the looting in Tikrit last year and reports of torture, revenge killings and kidnappings in Fallujah, a historic militant stronghold near Baghdad.

Although Sunnis are predominant in the northern and western provinces under militant control, Shiites are in the majority overall in Iraq.

The Sunnis in Mosul were mostly indifferent to the Daesh offensive of 2014 and some even supported it if it would end the oppression of the security forces under former Prime Minister Nouri al-Maliki, an ally of Iran. Maliki has since been succeeded by Abadi, another Shiite, who has taken a conciliatory approach toward the Sunnis and softened the alliance with Tehran.

Abadi has yet to decide whether the Shiite militias will take part in the offensive.

The former governor of Mosul, Atheel al-Nujaifi, a Sunni, told Reuters the local administration of the city should have more autonomy after the militants are dislodged. A police force reflective of the city’s complex ethnic and religious makeup should be in charge of security, not the army, added Nujaifi, who leads a Sunni militia that plans to take part in the offensive on Mosul alongside the army.

“The sweeping advance of Daesh in Mosul created a new reality,” Nujaifi said.

Younis, the teacher, and Mosulites who still live in the city said even though Daesh rule was much worse than government rule under Maliki, the population wouldn’t accept a return to the previous situation.

“Berlin after Hitler couldn’t possibly be like before and so should Mosul be after Daesh,” Younis observed. “We need a new system to govern Mosul, we cannot suffer more ordeals.”