Iraqi officials say a suicide blast targeting security forces and subsequent clashes with Islamic State militants have killed at least 23 troops and allied Sunni fighters in the embattled western province of Anbar.

The officials say a suicide bomber first struck a gathering of pro-government Sunni fighters near the town of al-Baghdadi on Tuesday morning. The town is about 110 miles northwest of Baghdad.

Soon after, Islamic State extremists attacked nearby army and police positions, setting off clashes. […]