As Sunni tribesmen and fighters enlisted with the Iraqi national police forces prepare to retake the key city of Ramadi in the country's western Anbar province, Shiite volunteer groups are attacking the Islamic State group in Fallujah, which borders Baghdad. The Islamic State group, also known as ISIS or ISIL, has controlled large swaths of land in Fallujah for several months, but recently made a push to take over complete control of the city, which lies less than 50 miles from the capital.

If ISIS succeeded in capturing all of Fallujah, it would would put Baghdad squarely in its crosshairs. Anticipating the Sunni militant group's advance, Shiite volunteer forces, also known as the Popular Mobilization Committee, launched an offensive in the area at the end of June.

The offensive in Fallujah is affecting the residents of the city. Several people Tuesday posted on social media accounts claiming the Iraqi and U.S.-lead coalition forces targeted ISIS militants in the city, but also hit innocent civilians.

The ISIS militants are dispersing themselves among the residents to avoid detection, Sunni sheikhs in the area said, making it difficult for the U.S. coalition to bomb them without also hitting civilians.

The Shiite fighters' offensive in Fallujah comes at the same time as Sunni tribesmen and the Iraqi security forces with the Defense Ministry plan to enter Ramadi in the coming week and take it back from ISIS.

The Shiite militias, largely backed by Iran, are not going to take part in the Ramadi operation, but said in interviews with International Business Times Tuesday they, specifically the Badr Organization, would secure areas surrounding Fallujah and would prevent the Sunni militant group from gaining ground closer to the capital. They said they would continue to station themselves in Saqlawiyah and Fallujah.

The U.S. coalition has been dropping bombs on Fallujah and its surrounding area for months, fighters said, but the attacks have not succeeded in eliminating ISIS's presence because many of the Sunni sheikhs in the area are supporting the militant group with cash and weapons. Some have even pledged allegiance to the group.

The apparently imminent attack on Fallujah comes as a new group of U.S. military advisers arrives in Anbar province to work with Iraqi counterparts to develop a strategy to defeat ISIS in Anbar. The U.S. advisers are arming and training a new group of Sunni fighters.

Thousands of people are still living in Fallujah, and ISIS is preventing them from leaving, Sunni fighters in Anbar said. Unable to leave their homes for safer ground, residents of Fallujah and surrounding villages are living under consistent bombardment from the U.S.-led coalition planes that are targeting ISIS hideouts.