The terror group known as ISIS has made progress in Iraq, forcing the country's military to bid a hasty retreat from the provincial capital of Ramadi. It is considered a major blow to both Iraq and the coalition led by the United States.

According to a combined report from CBS News and the Associated Press, a spokesman for the governor of Iraq's Anbar province estimated on Monday that about 500 people, which comprised both civilians and Iraqi soldiers, were killed in the fighting at Ramadi, which fell to the terror group's control. This development showed that ISIS still had the capabilities to conquer new territory, despite constant airstrikes in both Iraq and Syria.

"We do not have an accurate count yet," spokesman Muhannad Haimour said. "We estimate that 500 people have been killed, both civilians and military, and approximately 8,000 have fled the city."

CBS News reported that video has been posted online of Humvees, trucks and other equipment hastily moving out of the city. Local officials stated that ISIS militants have carried out mass killings of Iraqi security forces and civilians.

According to a Fox News report, Ramadi is located just 80 miles from Baghdad. One U.S. military official conceded that the fight for Ramadi was "pretty much over for now."

"The situation in the city is absolutely terrible," Haimour said. "The city is in very bad shape."

U.S. Secretary of State John Kerry, who is currently traveling through South Korea, told reporters that he is still confident in the fight against ISIS despite the loss of Ramadi. According to CBS News, he has previously stated that the fight against ISIS would be a long one.

"In Anbar, where you don't yet have the presence of the Iraqi security forces in the full numbers necessary to take the fight to Da'esh (Arabic acronym for the ISIS) everywhere yet, I underscore 'yet,' there are targets of opportunity, like in Ramadi or somewhere else, where Da'esh has the ability to inflict great damage," Kerry said.

According to CBS News, the fall of Ramadi was an echo of how Iraqi security forces collapsed last summer when ISIS suddenly captured a third of Iraq. The development also brought questions related to the Obama administration's strategy to take out the militant group through airstrikes.

"We welcome any group, including Shiite militias, to come and help us in liberating the city from the militants. What happened today is a big loss caused by lack of good planning by the military," Sunni tribal leader Naeem al-Gauoud told the Associated Press.

One senior U.S. military official told Fox News indicated that Iraqi forces "were pushed out by a much smaller [ISIS] force." That official was asked if the U.S. military would increase its involvement in the aftermath of that development.

"The Iraqis have to want it more than we want it," the official said.