U.S. Secretary of State Hillary Clinton is urging Iran to provide information about three missing American tourists who are believed to have been detained Friday in Iran on charges of entering from Iraq without permission.
Clinton told reporters at the State Department that, as of Monday morning, the U.S. did not even have official confirmation that Iran is holding the three Americans.
She said the U.S. is working through the Swiss embassy in Tehran to determine the trio's whereabouts and bring them home. The United States and Iran do not have diplomatic ties.
Iranian state-run media Sunday quoted an Iranian lawmaker, the head of the Iranian Parliament's foreign policy committee, Alaeddin Boroujerdi, as saying "the case is currently on its natural course." He did not provide any further information.
The head of security in northern Iraq's Kurdish region, Hakem Qadir, says the three went to see a waterfall near the Iraq-Iran border, but apparently ventured into neighboring Iran.
They were surrounded by Iranian soldiers and arrested.
The border in the mountainous region is not well-marked.
Family members of one of the detained Americans, Josh Fattal, told reporters Sunday they are concerned for the trio's well-being.
Kurdish officials say at least two of the detained hikers had been studying Arabic in Syria. They had entered Iraq's semi-autonomous Kurdish region from Turkey.
Some information for this report was provided by AP.