U.S. arrest of Iranians reportedly upsets Iraqi president

BAGHDAD, Iraq (CNN) -- Iraqi and Iranian authorities slammed the United States on Monday for having arrested several Iranians who were visiting Iraq.

A U.S. official said the Iranians were suspected of involvement in attacks against Iraqi security forces.

Iranian Foreign Ministry spokesman Seyyed Mohammad Ali Hosseini warned that "this action is not justifiable by any international rules or regulations and will have unpleasant consequences," Iran's semi-official Mehr news agency reported.

A spokesman for Iraqi President Jalal Talabani said Talabani had invited the Iranians to the country, and the president was "unhappy" about the arrests.

The U.S. National Security Council confirmed that the American military arrested at least four Iranians in raids during the past week in Iraq, including two diplomats.

NSC spokesman Gordon Johndroe said the two diplomats were questioned, turned over to the Iraqi government and released.