At least 77 people are confirmed to have died after a commercial IranAir passenger jet crashed in the country's north.
Iranian president Mahmoud Ahmadinejad has ordered an inquiry into the crash, and investigators have now recovered the flight recorders from the wreckage of the Boeing 727.
Al Jazeera's Alireza Ronaghi in Tehran reported that bitter cold and roughly 70cm of snow have hampered rescue efforts.
The aircraft crashed at around 16.15GMT on Sunday evening, and was bound from Tehran towards Orumiyeh, officials said.
Al Jazeera's Caroline Malone reports.