The United States says it does not have official confirmation that three missing Americans are being detained in Iran on charges of entering the country from Iraq without permission.

U.S. State Department Spokesman Robert Wood said Wednesday there are no reasons to doubt Iranian reports that the three were arrested Friday near the Iraq-Iran border.  But he said the U.S. cannot seek consular access until the Iranian government provides official confirmation of the arrests.

The U.S. does not have diplomatic ties with Iran and is working through the Swiss ambassador in Tehran to obtain information.  Wood said the ambassador contacted Iran's Foreign Affairs Ministry on Tuesday, and the ministry has said it will try to get information on the trio.

Also Tuesday, Iran's semiofficial Fars news agency (Tuesday) quoted a deputy governor of Iran's Kordestan province (Iraj Hassanzadeh) as saying the three Americans were being interrogated and had not confessed to any crime. 

Iranian television has described the trio as spies.  The head of security in northern Iraq's Kurdish region, Hakem Qadir, says the three were traveling through northern Iraq and apparently ventured into Iran when they went on a hike to see a waterfall near the border. 

Kurdish authorities in Iraq say the border with Iran is not clearly marked in the area where the Americans were arrested.  They say at least two of the travelers had been studying Arabic in Syria, and that they had entered Iraq's semi-autonomous Kurdish region from Turkey.

A somewhat similar case involving U.S. journalists who were imprisoned after allegedly crossing into North Korea without permission ended happily Tuesday.  Former U.S. President Bill Clinton secured the release of the two detained women who have returned to the United States. 

U.S. spokesman Wood cautioned (Wednesday) that people cannot assume that the situation in Iran will be handled in the same manner, saying each situation must be evaluated on its merits.