BAGHDAD, Iraq (CNN) -- Two Americans were killed in Baghdad's heavily fortified Green Zone, one in a rocket attack and the other under mysterious circumstances, officials in Iraq said.
An American man was found bound, blindfolded and fatally stabbed in a car Friday in the district, formally known as the International Zone, Iraqi security forces said Saturday.
Iraqi officials and the U.S. military were investigating the killing in the Green Zone, which houses Iraqi government offices and the U.S. Embassy.
The victim's throat apparently had been slit and he was stabbed multiple times, Iraqi security forces said. The man was found in a sport utility vehicle. His hands were tied behind his back.
Iraqi security forces found an identification on the man and said he appears to be in his 50s.
A U.S. military official said the victim's name could not be released until his family was notified.
Also, an American civilian was killed when a rocket landed in the zone on Friday night, the U.S. military said on Saturday.
The civilian was a Defense Department employee, and the rocket landed north of the U.S. Embassy. A witness told CNN the rocket struck a trailer and that the civilian was preparing to leave Iraq next week.
In January, the U.S. military handed over security of the International Zone to Iraqi security forces.
CNN's Mohammed Tawfeeq contributed to this report.