Iran has detained three Americans who crossed the border from northern Iraq, Iranian state television confirmed Saturday. Iran says the trio, two men and a woman, failed to heed warnings from Iranian guards.

Authorities in Iraq's self-ruled Kurdish region say the Americans were hiking and accidentally crossed the border.

Qubad Talabani, the Kurdish regional government's envoy to Washington, told The Associated Press, they mistakenly hiked into the border town of Ahmed Awaa.

"The Iranians said they have arrested them because they entered their land without legal permission," Talabani said Saturday.

U.S. State Department spokesman Robert Wood said that Washington has asked the Swiss, who represent the U.S. in Iran, to "to confirm these reports with Iranian authorities and, if true, to seek consular access" to the arrested Americans.

A security official in Sulaimaniyah -- located in northern Iraq's oil-rich Kurd region -- said the three hikers contacted a friend and said they had been surrounded by troops after they entered the Iranian territory by mistake.

The friend was supposed to taking part in the same excursion, but was too sick to tag along, the official said.

CNN reporter Arwa Damon told Â鶹´«Ã½ Channel that the hikers strayed across the border in a mountainous area that lacks a defined border.

"It's right up against the Iranian border, it's a beautiful mountainous region, lots of natural beauty there, waterfalls," Damon said in a phone interview from Baghdad on Saturday morning.

Damon said the Americans had been warned about the dangers of getting too close to the Iranian border.

"The tourist police at this area ran into them at some point prior to this phonecall and told them that they were close to the border, that they needed to be careful because they are American and not Iraqi, and that these are very tense times," Damon said.

A Kurdish border force official said the four Americans had originally travelled from Turkey into the Kurdish region on Tuesday. They then visited the Kurdish cities of Irbil and Sulaimaniyah on Wednesday and three of them took a taxi to Ahmed Awaa on Thursday.

Damon said two of the Americans are students in Syria, and that the group had travelled to Turkey from Syria.

With files from The Associated Press