This is breaking news on BBC (link to original)
A US plane has been forced to land in Iran after violating Iranian territory, the Iranian semi-official Fars news agency has reported.
It said the Falcon aircraft entered Iranian airspace from Turkey, flying at low altitude to avoid radar.
The agency said the plane was detected by Iranian fighter jets, which forced it to land at an undisclosed airport.
Passengers included five senior American generals and three civilians, the report said.
The agency said the group was interrogated at the airport and then allowed to leave after it was realised they had entered unintentionally.
[Apparently the Pentagon has denied the story, saying it was unaware of any warplanes being forced to land in Iran.]