Iran has confirmed it detained three Americans who were in the area of the Iranian border while on a hiking trip, Kurdish officials said on Saturday.
The US State Department has said it was looking into the situation.
The Kurdish regional government's envoy to Washington, Qubad Talabani, told The Associated Press the three were tourists and are in Iranian custody. He said the Americans mistakenly crossed into Iranian territory yesterday at the border town of Ahmed Awaa.
"The Iranians said they have arrested them because they entered their land without legal permission," he said.
Iranian officials have made no comment. Iran's embassy in Baghdad was closed on Saturday.
The self-ruled Kurdish region has been relatively free of the violence that plagues the rest of Iraq. Foreigners often feel freer to move around without security guards in the area, and tourists have been known to visit the scenic area.
The Kurdish government generally grants visitors to the Kurdish area visas valid for one week when they arrive at the airport.
A senior security official in Sulaimaniyah, near the Iranian border in northern Iraq's oil-rich Kurd region, said today the three were last heard from after they contacted a friend saying they entered Iran by mistake and troops surrounded them.