The pilots were assigned to Task Force Marne. Their names were withheld pending notification of family members, CNN reported.
"There were no enemy forces present and no hostile fire was reported," military officials said in a statement.
At least 10 Sunni worshippers were wounded Sunday in a suicide bomb attack outside a mosque near Tikrit, police said. Iraqi investigators believe al-Qaida in Iraq was responsible for the bombing, CNN reported.
Authorities were seeking gunmen who killed a police officer near his home in Mosul, officials told the Kuwait news agency KUNA. No group had claimed responsibility for the slaying, police said.
Kirkuk police said a civilian was injured in a blast out the rural district of Al-Huwaija. Again, no suspects were in custody.