US-led coalition air and artillery strikes have killed 70 Islamic State fighters in Fallujah, including the jihadists' leader in the Iraqi city, a military spokesman said Friday.

Baghdad-based Colonel Steve Warren said that over the last four days, 20 strikes in the besieged city had destroyed IS fighting positions and gun emplacements. 

"We've killed more than 70 enemy fighters, including Maher Al-Bilawi, who is the commander of ISIL forces in Fallujah," Warren said, using an acronym for the IS group.