The United States and its allies have staged 22 airstrikes on Islamic State targets since Friday, May 22, including four near Ramadi, the city taken by the militants this week, the U.S. military said on Saturday, according to Reuters.

Coalition forces also attacked five Islamic State sites in Syria between Friday and Saturday, a statement from the Combined Joint Task Force said.

The strikes near Ramadi hit tactical units, armored vehicles and a fighting position in militant-controlled territory. Ramadi fell to Islamic State on Sunday in a serious setback for Iraqi forces that also cast doubt on the U.S. strategy of using mainly air strikes against the militants.

The other U.S.-led attacks in Iraq were near the cities of Al Asad, Bayji, Fallujah, Haditha, Kirkuk, Makhmur, Mosul, Sinjar and Tal Afar. Islamic State tactical units, vehicles, fighting positions, heavy machine guns and buildings were hit.

In neighboring Syria, air strikes near Al Hasakah, Dayr Az Zawr, Kobani and Tadmur destroyed fighting positions, a tank and six anti-aircraft artillery systems, the joint task force said.