The Islamic State is killing dozens of its own in a frantic hunt for traitors, immersing some in vats of acid

In March, a senior commander with the Islamic State group was driving through northern Syria on orders to lead militants in the fighting there when a drone blasted his vehicle to oblivion.

The killing of Abu Hayjaa al-Tunsi, a Tunisian jihadi, sparked a panicked hunt within the group’s ranks for spies who could have tipped off the US-led coalition about his closely guarded movements. By the time it was over, the group would kill 38 of its own members on suspicion of acting as informants.

They were among dozens of IS members killed by their own leadership in recent months in a vicious purge after a string of airstrikes killed prominent figures. Others have disappeared into prisons and still more have fled, fearing they could be next as the jihadi group turns on itself in the hunt for moles, according to Syrian opposition activists, Kurdish militia commanders, several Iraqi intelligence officials and an informant for the Iraqi government who worked within IS ranks.

The fear of informants has fueled paranoia among the militants’ ranks. A mobile phone or internet connection can raise suspicions. As a warning to others, IS has displayed the bodies of some suspected spies in public — or used particularly gruesome methods, including reportedly dropping some into a vat of acid.

IS “commanders don’t dare come from Iraq to Syria because they are being liquidated” by airstrikes, said Bebars al-Talawy, an opposition activist in Syria who monitors the jihadi group.

Over the past months, American officials have said that the US has killed a string of top commanders from the group, including its “minister of war” Omar al-Shishani, feared Iraqi militant Shaker Wuhayeb, also known as Abu Wahib, as well as a top finance official known by several names, including Haji Iman, Abu Alaa al-Afari or Abu Ali Al-Anbari.

Rami Abdurrahman, who heads the Britain-based Syrian Observatory for Human Rights, said some IS fighters began feeding information to the coalition about targets and movements of the group’s officials because they needed money after the extremist group sharply reduced salaries in the wake of coalition and Russian airstrikes on IS-held oil facilities earlier this year.