The leader of ISIS in Syria has been killed in an air strike, the The United States Central Command has claimed in a statement.

Maher al Agal, one of the group’s top five leaders, was targeted along with a second unidentified ISIS official and killed outside Jindayris, in northwest Syria on Monday.

“A senior ISIS official closely associated with Maher was seriously injured during the strike,” the military said. “Extensive planning went into this operation to ensure its successful execution. An initial review indicates there were no civilian casualties.”

According to the statement al Agal was responsible for developing ISIS networks outside of Iraq and Syria, and his death is expected to disrupt the group’s ability to plot and carry out attacks on an international level.

The strike comes just months after the head of the group in February blew himself up along with members of his family during an American raid on his hideout in Syria, according to the U.S.

The killing of al Agal will also deal a blow to the militant group’s efforts to regroup and reorganize within Syria and Iraq after losing large swathes of territories since their rise to power in 2014.

At the height of their rule ISIS controlled more than 40,000 square miles and more than eight million people. Today they have reverted to guerilla tactics, including a wide-scale attack earlier this year on al Sina prison in the northeastern city of Hasakah.

According to the Washington-based Carnegie Endowment for International Peace the attack on Sina prison was “a stark reminder of ISIS’ organizational strength that had been long forgotten since the fall of the border town of Baghouz in March 2019 when former American president Donald Trump announced the collapse of the group’s territorial caliphate”.

On Tuesday in northeast Syria the Kurdish-led Syrian Democratic Forces (SDF) said they had thwarted an ISIS plan to release the group’s family members from al Hol camp, where 55,000 people from Syria, Iraqi and some 60 other countries are housed.