Iranian President Mahmud Ahmadinejad has ordered an investigation after an Iran Air plane crashed, killing 77 people as it broke up into pieces in heavy snow and fog.
State television said the Boeing 727 carrying 105 people crashed near the northwestern city of Orumiyeh
on January 9 after it took off from Tehran.
The ageing U.S.-built aircraft was reportedly delivered to Iran back in 1974.
Media reports said dozens of people were also injured in the crash, and some were in serious condition.
Transport Minister Hamid Behbahani said Ahmadinejad has ordered a probe into the crash, adding that the "preliminary reason" for the accident was "lack of visibility and fog."
Iran, under years of international sanctions, has suffered several aviation disasters over the past decade.
Its civil and military fleet is made up of ancient aircraft in very poor condition because of their age and lack of maintenance. compiled from agency reports