The Iran Air Boeing 727 crashed while attempting to land in bad weather with 106 on board, officials said. At least eight of the injured were in a critical condition.
"So far, 52 out of 77 victims have been identified and among the fatalities there were 36 men and 16 women," IRNA quoted deputy head of Azarbayjan-e Gharbi coroner's office, Hamid Davoudabadi, as saying.
The semi-official Mehr news agency said four Iraqi nationals were among those killed.
Ahmad Majidi, head of the crisis management office at the Transport Ministry, told ISNA news agency that the flight had taken off from Tehran in good visibility.
By the time the plane arrived in the city of Urumiyeh, in a mountainous area near the border with Turkey, about 1,000 km (600 miles) northwest of the capital, there was zero visibility due to snow and fog, state TV said.
LIGHTS WENT OUT
Survivor Hossein Haqiqi said the pilot announced an emergency landing. "Then, exactly like in the movies, the plane hit the ground and the lights went out. I fainted and was not conscious of anything," ISNA quoted him as saying.
Another passenger, Nasrin Fatahzadeh, said rescuers cut through the plane's seats to pull her free.
President Mahmoud Ahmadinejad ordered an accelerated investigation while IRNA reported the plane's black box flight recorder had been found.
"The government has announced three days of mourning in the province," IRNA said.
State television showed the wreckage of the plane, which appeared to have broken into several sections on impact. Huge gaps were torn in the fuselage.
Iran has suffered several crashes in the past few decades. Tehran says U.S. sanctions have prevented it from buying new aircraft or spare parts from the West.
The last major air crash in Iran was in July 2009, when a Caspian Airlines Tupolev aircraft bound for Armenia caught fire in mid-air and crashed into farmland near the city of Qazvin, killing all 168 people on board.
One of the country's worst air accidents was in February 2003 when an Iranian Ilyushin-76 troop carrier crashed in southeast Iran, killing all 276 Revolutionary Guard soldiers and crew aboard.