Tehran is to hold its first international marathon but two days ahead of the expected race, Iran's Track and Field Federation chief cannot confirm whether Americans will participate.
The official, Majid Keyhani, says there is no ban on any nationality participating in what he called the "Persian Run." But he would not confirm which countries will be represented.
He also says that women will be forced to run separately from men.
The website for Friday's race lists 28 Americans among the registered runners, along with participants from more than 40 countries, including Britain, Germany and Canada
Keyhani says more than 50 women have signed up but that they will have to run separately from men in a stadium and that only men are allowed to run on Tehran streets.