BAGHDAD — A suicide blast targeting Iraqi security forces and subsequent clashes with Islamic State extremists on Tuesday killed at least 23 troops and pro-government Sunni fighters in the country’s embattled western province of Anbar, officials said.

The day’s heavy toll for the Iraqi forces came as they struggle in battles against the Islamic State group and try to claw back territory lost to the extremists during the militants’ blitz last year. Iraq’s prime minister vowed on Tuesday to dislodge IS militants from all areas under their control.

Police officials said a suicide bomber first struck a gathering of pro-government Sunni fighters near the town of al-Baghdadi, about 180 kilometers (110 miles) northwest of Baghdad, in the morning hours.

Soon after, IS militants attacked nearby army and police positions, setting off hours-long clashes. Police and hospital officials said 23 were killed and 28 were wounded in all on the government side. They did not give the death toll on the militants’ side, saying only that the attackers “sustained some casualties” and declining to provide further details. All officials spoke on condition of anonymity because they were not authorized to speak to the media.

In Baghdad, Prime Minister, Haider al-Abadi pledged that Iraq’s forces would retake all areas that fell to IS during last summer’s stunning blitz.

“We will emerge as victorious and the day our lands are liberated is nearing,” al-Abadi told a group of newly-graduated army officers, speaking at the Military Academy as Iraq marked Army Day. “Our goal … is that peace and prosperity prevail in Iraq and end this dark period in Iraqi history.”