The Iraqi forces tasked with securing Ramadi and removing any remaining links to the Islamic State insurgency that once controlled the city are encountering improvised explosive devices and evidence of the group’s brutal treatment of civilians, a Pentagon spokesman said Wednesday.

Col. Steve Warren, the spokesperson for the United States-led coalition against the Islamic State, held a news briefing with reporters and provided updates on the campaign’s efforts as it helps the Iraqi military take back the city and takes other actions against the terrorist group.

Iraqi officials announced that the country’s military had raised the flag over a government complex in Ramadi on Dec. 28, some seven months after the Islamic State took control of the capital of Anbar province. The military has spent the ensuing days working to clear the rest of the city, Warren told reporters at the news briefing, but was still encountering some resistance.

Warren said the Iraqis needed to dismantle improvised explosive devices on an “almost house-by-house” basis, and the group was also encountering sniper fire from lingering enemies. Warren said about 60 Islamic State insurgents were killed in the past 24 hours, though multiple groups of up to a dozen fighters remained. He didn’t estimate the total number of fighters left in Ramadi, but said the coalition was helping the Iraqis clear neighborhoods with airstrikes.

As the Iraqi forces moved into smaller neighborhoods, Warren said they came across civilians who had been killed “execution-style,” some who were shot as they tried to flee, others injured by improvised explosive devices and some who the Islamic State used as human shields.

Warren told reporters that many surviving civilians were being taken to stations in the city where they received food, water and healthcare. If they had no place to go, Warren said the civilians were often being relocated to Habbaniyah, where there are camps for displaced people.

Approximately 100 members of the Iraqi military died as they worked to recapture Ramadi, Warren said, adding it was difficult to tell how long it would take for the city to be fully cleared.

The progress in Ramadi is just one small victory in the ongoing fight against the Islamic State, though Warren touted several of the coalition’s recent accomplishments on Wednesday.

Warren wrote on his Twitter page that the Islamic State has lost between 7,700 and 8,500 square miles of territory in Iraq alone, and have not captured any new territory since May. He told the news conference that represented about 40 percent of the territory it once controlled.

The Iraqis still must liberate significant portions of the country that are held by the Islamic State, Warren told reporters, though there wasn’t any indication as to where they would go next.

“Whatever they decide is their next focus, this coalition will be there prepared to support them through the air, as well as with training and equipment,” Warren said during the media briefing.

Warren also told reporters the coalition’s airstrikes killed 2,500 Islamic State fighters last month, but estimated between 20,000 and 30,000 were still operating inside Iraq and Syria.

Warren estimated the Islamic State had not lost as much territory in Syria. He told reporters that the group only lost about 700 square miles in Syria, roughly 10 percent of what it held there.

The colonel also gave an update on the coalition’s campaign against the Islamic State’s oil smuggling, a major source of income for the terrorist organization. He estimated the coalition has reduced the group’s oil revenue by about 30 percent since the campaign began, and said that the Islamic State’s total oil production dropped by about 24 percent to 34,000 barrels every day.

“In addition to chipping away at their so-called caliphate (and) killing their leaders, we’re also hitting them in the pocketbook,” Warren told reporters.