At least two dozen Iraqi security forces were killed in suicide attacks launched by ISIL on Sunday in restive Anbar province, the scene of near-daily violence.

The news comes as the United States announced the deployment of more US Marines on the ground to fight the Islamic State of Iraq and the Levant, also known as ISIS.

An Iraqi military source told Al Jazeera at least 24 Iraqi forces were killed, while 12 others were wounded in the blasts in the municipality of Haqlaniyah, southwest of Hadeetha city.

ISIL fighters with explosive vests snuck into Haqlaniyah and at least three entered a municipal building and detonated their explosives.

Clashes were ongoing between ISIL and Iraqi soldiers backed by popular mobilisation forces, said the source on condition of anonymity.

Last week, at least 47 Iraqi soldiers were killed in a series of attacks by ISIL fighters near Anbar's strategic city of Ramadi.

Residents of Anbar account for more than a third of the 3.2 million people displaced by fighting in Iraq since the start of 2014, according to the International Organization for Migration.

US marine killed

The US military said on Sunday troops from the 26th Marine Expeditionary Unit will add to the American forces already in Iraq battling ISIL.

A US Marine was killed in an ISIL rocket attack in northern Iraq on Saturday, the Pentagon said, the second American combat death in the fight against the group.

The rocket barrage occurred in the autonomous region of Kurdistan, where Baghdad has recently been deploying forces to prepare for an offensive against ISIL-controlled Mosul city.

"Several other Marines were wounded and they are being treated for their varying injuries," the Pentagon said in a statement.

Under a stepped-up campaign of US-led and Russian air strikes, as well as ground assaults by multiple forces in each country, ISIL is estimated to have lost about 40 percent of its territory in Iraq and more than 20 percent in Syria.

At its highest point in the summer of 2014, the group had overrun nearly a third of each country, declaring a "caliphate" spanning from northwestern Syria to the outskirts of Baghdad.

At that time, ISIL fighters were riding high, known for their courage, experience, readiness to die and brutality. Now, those battling them on the ground say they appear to be flagging.

"What we are witnessing is that Daesh are not as determined as they used to be," said Lieutenant Colonel Fares al-Bayoush, commander of a Syrian rebel faction, using an Arabic acronym to refer to ISIL.

"Now there are members who surrender, there are some who defect. In the past, they used to blow themselves up."

Al Jazeera