BAGHDAD - Suicide bombings at checkpoints in Baghdad and south Iraq claimed by the Islamic State group killed at least 35 people and wounded dozens more, officials said on Saturday.

The bombings, which hit Iraq the previous night, came as Iraqi forces battle IS in Mosul in a massive operation launched more than seven months ago to retake the country’s second city from the jihadists.

In Baghdad, suicide car bombers attacked in the area of a checkpoint in the city’s southern Abu Dsheer area, killing 24 people and wounding 20, Brigadier General Saad Maan told AFP.

Security forces were able to kill one of the attackers, but the second blew up his car bomb, Maan said.

IS issued a statement claiming the attack but gave a different account of how it unfolded, saying that one militant clashed with security forces using a light weapon before detonating an explosive belt, after which a second blew up a car bomb.

And in south Iraq, a suicide bomber blew up an explosives-rigged vehicle at a checkpoint on the outskirts of the city of Basra, killing 11 people and wounding 30, according to Riyadh Abdulamir, the head of Basra province health department. Another militant who left a second explosives-rigged vehicle was killed by security forces, the Basra Operations Command said.

IS also claimed the Basra attack, but said that both bombs were successfully detonated. The jihadist group overran large areas north and west of Baghdad in 2014, but Iraqi forces backed by US-led air strikes have since recaptured much of the territory they lost to the jihadists.

Security in Baghdad improved following the 2014 IS assault, presumably because the jihadists were occupied with fighting and control of territory elsewhere in the country. After recapturing the cities of Tikrit, Ramadi and Fallujah, Iraqi forces launched an operation to retake Mosul - at the time the largest population centre still in IS hands - last October. They have recaptured the city’s east and are now fighting to retake a dwindling number of areas still under IS control in west Mosul.

Half a million people are currently displaced as a result of the battle for Mosul, and around 250,000 civilians are estimated to still be trapped inside the city’s west. The presence of the civilians, who either chose not to leave or were prevented from doing so by IS, complicates any final assault to seal victory in Mosul.

Human shields have become a central feature of the vastly outnumbered jihadists’ defences, and IS has stopped at nothing to deter people from escaping the city, including killing people who seek to flee. And the recapture of the city will not mark the end of the IS threat: the jihadists also control territory along the Syrian border and in Kirkuk province, as well as areas in Syria itself.

Experts warn that the jihadists may increasingly turn to bombings targeting civilians and hit-and-run attacks on security forces as they lose additional ground. Members of the Islamic State group have ‘executed’ 19 civilians including two children in a village held by anti-jihadists in eastern Syria, the Syrian Observatory for Human Rights said Saturday.

“IS fighters entered Jazrat al-Boushams village on Friday evening and executed 19 civilians, including two women and two children, with bullets to the head before torching the corpses,” Rami Abdel Rahman of the Britain-based monitor told AFP. Meanwhile, President Donald Trump has instructed the Pentagon to “annihilate” the Islamic State group in Syria in a bid to prevent escaped foreign fighters from returning home, Defense Secretary Jim Mattis said.

The move to encircle then kill as many jihadists in place as possible - rather than letting them exit a city and targeting them as they flee - reflects an increased urgency to stop battle-hardened jihadists bringing their military expertise and ideology back to European capitals and other areas. The president has “directed a tactical shift from shoving ISIS out of safe locations in an attrition fight to surrounding the enemy in their strongholds so we can annihilate ISIS,” Mattis said, using an acronym for IS. “The intent is to prevent the return home of escaped foreign fighters.” Trump, who campaigned on a pledge to quickly defeat IS, signed an executive order soon after taking office giving his generals 30 days to come up with a revised plan to wipe the jihadists out.

The review resulted in the new “annihilation campaign” and saw commanders gain greater autonomy to make battlefield decisions. Critics of Barack Obama’s administration frequently complained of White House micromanagement and a lengthy approval process causing delays on the ground. Mattis called foreign fighters a “strategic threat” should they return home and said the annihilation effort would prevent the problem from being transplanted from one location to another.

The US-led coalition has been battling IS since late summer 2014, supporting local fighters on the ground with a combination of considerable air support, training and weaponry.

Trump this month authorized the United States to arm the Kurdish faction of an alliance fighting IS in northern Syria, much to the consternation of Turkey, which views them as terrorists.

Though the jihadists have lost 55 percent of the territory they once held in Iraq and Syria and over four million people have been liberated, IS still controls the Syrian stronghold Raqa, swaths of the Euphrates River valley and other areas including a small part of Mosul in Iraq.

Operations in Syria are further complicated by the country’s tangled knot of groups fighting in the civil war.

Russia joined that conflict in late 2015 to prop up President Bashar al-Assad, bringing a new dimension of complexity and risk.

General Joe Dunford, who chairs the Joint Chiefs of Staff, noted the US is working successfully with Russia to “deconflict” military operations in Syria.

The two sides established a hotline to inform each other of their forces’ location to avoid any mishaps.

Dunford hinted the US had a “proposal” to further enhance deconfliction, but he didn’t give any details. “My sense is that the Russians are as enthusiastic as we are to deconflict operations and ensure that we can continue to take the campaign to ISIS and ensure the safety of our personnel,” he said.

Separately, the Pentagon announced that Dunford has been nominated to serve a second two-year term in his job as the country’s top military officer.