At least 15 fighters from the militant terrorist group Islamic State (IS) were killed and at least six US soldiers wounded in a US military operation in Iraq on Thursday, three US defense officials said.

None of the U.S. soldiers’ injuries were described as life-threatening. Several were possible traumatic brain injuries and at least one soldier suffered external injuries, defense officials said.

The operation took place on Thursday in Anbar in western Iraq, officials said. Some of the ISIS members killed were senior leaders.

The US Central Command said in a statement on Friday evening that the joint raid with Iraqi security forces took place early Thursday.

The ISIS agents were “armed with numerous weapons, grenades and explosive suicide belts,” said the command, abbreviated as CENTCOM.

“This operation targeted ISIS leaders to disrupt and degrade ISIS’s ability to plan, organize, and conduct attacks against Iraqi civilians, as well as U.S. citizens, allies, and partners throughout the region and beyond,” it said.

There was no evidence of civilian casualties, the CENTCOM statement said.

“Iraqi security forces continue to exploit the raided locations,” it said.