The three were arrested in 2009 after they crossed into Iran from Iraq on foot. The Americans contend they strayed across the border accidentally while on a hiking trip, but Iran said they crossed into the country intentionally and had ties to U.S. intelligence.
Shourd was released on bail in 2010 and returned to the United States and is being tried in absentia. Fattal and Bauer faced their first court session in February.
Iran's Press TV said the prosecutor's office did not state directly that the trial would resume behind closed doors; however, that is standard practice in such cases.