One U.S. soldier was killed as American Special Forces conducted a joint raid with Iraqi forces to free dozens of Kurdish hostages in Northern Iraq, a U.S. defense official told CBS News national security correspondent David Martin on Thursday.

About 70 hostages were rescued in the operation, which local witnesses told CBS News was essentially a raid on a prison run by militants from the Islamic State of Iraq and Syria (ISIS) near the city of Hawija, in the largely Kurdish province of Kirkuk.

Local witnesses told CBS News that a number of ISIS militants were believed to have been captured by the U.S. and Iraqi forces, but those reports were not immediately confirmed by American officials.

In February of this year, ISIS posted videos online showing militants parading captured Kurdish Peshmerga fighters in cages through the streets of Hawija.

The Peshmerga have been one of the most reliable and successful forces on the ground fighting against ISIS in both northern Iraq and Syria, and the U.S. works closely with them.

The raid early Thursday morning took place east of Hawija, but U.S. officials had not confirmed the exact location. Locals said as many as four helicopters took part in the operation.