Iraq's parliament speaker says an airstrike targeting an Islamic State-held town in western Iraq near the Syrian border has killed and wounded "dozens" of civilians.

Speaker Salim al-Jabouri says the airstrike on Wednesday hit "unarmed civilians" in an urban area, described it as a "crime" and urging that the perpetrators "be punished."

It was unclear if the airstrike was carried out by Iraqi air force or the U.S.-led international coalition supporting the Baghdad government offensive against the Sunni extremist group.

Al-Jabouri did not provide specifics, or the breakdown of the casualties, but said he holds the Iraqi government responsible.

He also did not say how he came by the information. He demanded an immediate investigation.

Anbar province and Iraqi Defense Ministry officials were not available to comment.