A coalition of Iraqi security forces and tribal fighters killed a top ISIS commander Wednesday and took control of important positions in and around Fallujah during the third day of military operations in Anbar province, Iran’s Press TV reported.

The assault on Anbar, which began Monday, returns key portions of Fallujah to Iraqi government control after nearly 18 months in ISIS hands. Recapturing the city is strategically significant to the Iraqi government because it lies a mere 40 miles west of the capital, Baghdad. Denying ISIS a sanctuary in Fallujah also holds meaning for the U.S., however. An American attack to take the city from Al Qaeda in Iraq in 2004 resulted in more than 100 U.S. deaths and 1,500 enemy casualties.

Iranian-backed Shia militias referred to as Popular Mobilization Units claimed territory in the center of Fallujah and to the city’s south, according to Press TV. The network cited an Iraqi satellite network in reporting the retaking of an important bridge connecting a district near Ramadi to one north of Fallujah.

The coalition of Iraqi fighters, which also includes Sunni tribesman, killed 57 ISIS extremists, destroyed two tanker bombs and seized a pair of vehicles rigged with explosives on Tuesday, Press TV said. Airstrikes killed “scores” of ISIS terrorists.

ISIS is allegedly suffering such heavy losses in the Anbar fight that the terrorist group has barred civilians from entering or exiting hospitals in the northern city of Mosul in an attempt to keep casualty numbers quiet, according to the Lebanese NOW, translating a Kurdish Bas News article.

Operations also have started against ISIS fighters in Ramadi. Ramadi, the capital of the massive Anbar province, which borders Syria, Jordan and Saudi Arabia, is a little less than 80 miles from Baghdad. ISIS forces captured the city in May.

But while successful thus far, the maneuvers have not come without some criticism.

Iraqi military jets allegedly utilized so-called “barrel bombs” in an attempt to take Fallujah, according to Turkey’s state-run Anadolu Agency. Barrel bombs, empty oil drums packed with explosives, gained infamy after the Syrian government purportedly used them during the country’s ongoing civil war. The bombs contributed to the deaths of “at least 21 civilians” in Iraq on Tuesday and injured another 24, according to Anadolu.

If Fallujah is experiencing greater collateral damage than expected, however, there could be a reason.

ISIS has been preventing civilians from leaving Fallujah for more than three months and is using them as human shields, according to Bas News on Wednesday.

“Insurgents have planted improvised explosive devices in all of the city’s mosques and residential buildings and along the roads that lead to Fallujah,” Iraq High Commission for Human Rights member Fadel al-Gharaqi said in a statement obtained by Bas News.