The United States has said that it was investigating reports that three Americans have been abducted in northern Iraq.
"Embassy Baghdad is aware of the reports and is investigating," State Department deputy spokesman Robert Wood said on Friday, referring to reports he said were on Al-Jazeera Television, an Arab satellite station based in Qatar.
"We are using all available means to determine the facts in this case," Wood added.
There were few immediate details but unrest is growing in northern Iraq.
Diplomats and analysts warn that Kurdish demands to expand their autonomous region in northern Iraq to include the Kirkuk oil fields and other districts threaten to trigger armed conflict.