A fire at the Iranian Space Research Center has killed three scientists, a top Iranian official has announced.
Telecommunications Minister Mohammad Javad Azari Jahromi on February 3 said the scientists died as a result "of a fire in one of the buildings of the Space Research Center."
He did not provide further information about the incident at the Tehran site.
The names and positions of the victims were not immediately provided.
One report said staffers in another part of the research center were celebrating the 40th anniversary of the Islamic Revolution when the fire broke out.
Iran's space program has contributed to heightened tensions between Washington and Tehran.
President Hassan Rohani has said Iran soon will put two satellites into orbit using domestically made rockets, despite U.S. concerns that the launches could help further develop the country's ballistic missiles.
U.S. Secretary of State Mike Pompeo warned Iran not to proceed with "provocative" plans to launch new rockets, claiming they were "virtually identical" to nuclear-capable ballistic missiles and would violate a UN resolution.
Over the past decade, Iran has sent several satellites into orbit and in 2013 launched a monkey into space.
The program has had mixed results. Tehran on January 15 said it conducted a satellite launch but that the rocket failed to reach orbit.
Jahromi told state TV at the time that the rocket carrying the Payam (Message) satellite failed to reach the "necessary speed" in the third stage of launch.