The network's Web site quoted a wire story saying the three Americans were backpackers and that a Kurdish official had warned them not to hike in the mountains because of the proximity of the Iranian border.

Officials say the case is under investigation, Press TV said.

Four Americans -- two of them students in Syria -- had traveled from Syria to Turkey and then into northern Iraq's Kurdish region, according to Peshrow Ahmed, spokesman for the security manager of Sulaimaniya. The travelers arrived at Irbil on Tuesday, then drove Thursday to Sulaimaniya, Ahmed said.

All four spent the night at the Nirwan Hotel, according to owner Mudhafer Mohammed.

Three members of the group left early Friday in a taxi for Ahmed Awa, near Iraq's border with Iran, planning to hike in the mountains there, Ahmed said. The fourth member of the group was ill and stayed behind.

The taxi driver dropped the three off near the border and returned to town, he said.

Ahmed Awa police spotted the hikers at one point on Friday, Ahmed said, and warned them that they were near the Iranian border -- which is not marked in the area -- and that they should be careful.

The group was in contact with their companion in Sulaimaniya until about 1:30 p.m. Friday, when they reported they were "surrounded by Iranian soldiers," Ahmed said. No further communication was received.

Officials in Sulaimaniya are meeting to devise a strategy to bring the hikers home safely, Ahmed said.

U.S. State Department deputy spokesman Robert A. Wood said Saturday that officials have seen Iranian media reports about the detentions.

He said Swiss diplomats have been asked "to confirm these reports with Iranian authorities and, if true, to seek consular access."

"The protection of American citizens is our highest priority," Wood said.

The United States and Iran do not have diplomatic relations and Switzerland represents U.S. diplomatic interests in Iran.

Kurdish authorities said they had been trying to make contact with Iranian consular officials in Sulaimaniya. They also said a police patrol was dispatched and found a bag that contains the belongings of one of the three.

Mohammed, the hotel owner, told CNN that the hikers said they had come to the area because they heard it was safe, saying they were considering a trip to Ahmed Awa. But, he said, he advised them against it.

"I warned them many times," Mohammed told CNN.

"When they told me that they are planning to go to Ahmed Awa, I told them, 'Don't go there because it is unsafe for you because you're American and Ahmed Awa is very close to the Iranian border,'" he said.

The fourth American, the one who had stayed behind, left the hotel about 4:30 p.m. Friday, Mohammed said, asking him to take care of their luggage and saying he would not return. Later, he said, Sulaimaniya security forces took the luggage from the hotel.