U.S. Joint Chiefs Chair Army General Mark Milley speaks with U.S. forces in Syria at a U.S. military base in Northeast Syria
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The U.S. military killed a senior Islamic State leader in Syria on Monday, U.S. Central Command (CENTCOM) said on Tuesday, another blow to a group that was driven from its self-declared caliphate years ago but is still widely deemed a threat.

CENTCOM named him as Khalid 'Aydd Ahmad al-Jabouri in a statement, saying he was responsible for planning Islamic State attacks in Europe and Turkey and developed the group's leadership structure in Turkey.

Sources in Syria said he was killed in a drone strike in the rebel-held northwest, a region where other Islamic State leaders have hidden out, including former leader Abu Bakr al-Baghdadi, who died during a U.S. raid in 2019.

No civilians were killed or injured in the strike, CENTCOM said, adding that Islamic State "continues to represent a threat to the region and beyond".

"Though degraded, the group remains able to conduct operations within the region with a desire to strike beyond the Middle East," it said. Jabouri's death would "temporarily disrupt the group's ability to plot external attacks".

Islamic State controlled one third of Iraq and Syria at its peak in 2014. Though it was beaten back in both countries, Islamic State militants continue to wage insurgent attacks.

A regional intelligence source said Jabouri had been monitored for the last few months as he moved between the Syrian cities and towns of Hasaka, Raqqa, Jarablus and al-Bab, and was in Idlib province when he was killed.

"They got an informant tip that he is in Idlib so they put him under surveillance for a while and then executed the strike," the source said. He was killed while making a phone call, the source added.

Two local sources said he was attacked near his home on the outskirts of the village of Kaftin, a few kilometres (miles) from where Baghdadi was killed in 2019. He had been living with his wife and 12-year-old son.

He originally hailed from Deir al-Zor in southeastern Syria.

A U.N. report published in February said the threat posed by Islamic State and its affiliates to international peace and security was high in the second half of 2022 and had increased in and around conflict zones where it has a presence.

Islamic State is estimated to have 5,000 to 7,000 members and supporters spread between Syria and Iraq, roughly half of them fighters, the U.N. report said.

Northwestern Syria is controlled by a jihadist group that fought Islamic State earlier in Syria's 12-year-long war.

Late last year, Islamic State announced it had appointed a previously unknown figure - Abu al-Hussein al-Husseini al-Quraishi - as its leader after the previous leader was killed.

Islamic State once ran a third of Syria and Iraq according to its ultra-hardline interpretation of Islam, committing atrocities including the slaughter of thousands of Yazidis, and Islamic State militants carried out numerous attacks overseas including a rampage that killed 130 people in Paris in 2015.