AN Iranian commercial plane crashed overnight in a foggy, mountainous southern region of the country, killing all 66 people on board, state media reported.

An Aseman Airlines ATR-72, a twin-engine turboprop used for short-distance regional flying, went down near its destination of the southern Iranian city of Yasuj, some 780 kilometres south of the capital Tehran.

Aseman Airlines spokesman Mohammad Taghi Tabatabai told state TV that all on Flight No. EP3704 were killed.

“After searching the area, we learned that unfortunately ... our dear passengers had lost their lives,” Mr Tabatabai said. “This plane had 60 passengers, 59 adults and one child, as well as a pilot, a co-pilot, two flight attendants and two air marshals on board.”

PAST TECH FAILURE

The airline has dismissed the possibility of a technical failure and pinned the blame on severe weather conditions in the region, Al Jazeera reported.

But Iranian news website Roozarooz reported the aircraft had “technical problems midair during a recent flight a few weeks ago” and had to make an emergency landing.

The plane, an ATR-72, had recently re-joined the airline’s fleet after undergoing repairs for 7 years, The Guardian reported.

Aviation specialists suspected the plane could have been in the wrong position as it made it’s descent and hit the mountains.

“Basically it’s a failure of navigation. An airplane hitting mountains in clouds is like a ship hitting rocks,” aviation safety specialist David Learmount told Al Jazeera.

SEARCH FOR JET HALTED

The hunt for a plane that disappeared with 66 people onboard in Iran’s Zagros mountains was stopped until morning as blizzard conditions made progress impossible for rescue teams, state television said on Sunday.

“With the wind intensifying, and with snow, rain and darkness, it is not possible for rescue and relief teams to reach high altitudes and the search operation has been postponed until tomorrow,” broadcaster IRIB announced.

“Five helicopters are on alert to resume the search at dawn if the weather conditions are better.” Aseman Airlines flight EP3704 disappeared from radar 45 minutes after taking off from Tehran.

The ATR-72 twin-engine plane, in service for 25 years, left the capital’s Mehrabad airport at around 8:00 am (0430 GMT) and was heading towards the city of Yasuj, some 500 kilometres to the south.

The Red Crescent said 45 teams had been deployed to the Dena mountain of Iran’s southwestern Zagros range, but there was still no sign of any wreckage.

“The mountainous terrain is impassable. Thick fog and snow and rain have made it impossible to use helicopters,” said Morteza Salimi, head of its rescue and relief section.

IRAN MOURNS DEATHS OF THOSE ONBOARD

Iran’s leaders expressed their condolences over the crash.

Supreme Leader Ayatollah Ali Khamenei urged all related bodies on Sunday to apply their efforts “to heal the sorrow of the families and relatives of victims.”

In a message on his website, President Hassan Rouhani said he has assigned officials to investigate the case and apply measures to avoid similar incidents in future.

Due to foggy condition, rescue helicopters couldn’t initially reach the crash site in the Zagros Mountains, state TV reported. Mr Tabatabai said the plane crashed into Mount Dena, which is about 4400 metres tall.

A man who missed the doomed flight told reporters of his mixed emotions. “God has been really kind to me but I am so sad from the bottom of my heart for all those dear ones who lost their lives,” the unnamed man told the Tabnak news agency, which showed a picture of his unused ticket.

Aseman Airlines, owned by Iran’s civil service pension foundation, is a semi-private air carrier headquartered in Tehran that specialises in flights to remote airfields across the country. It also flies internationally. It is Iran’s third-largest airline by fleet size, behind state carrier Iran Air and Mahan Air. However, Aseman Airlines is banned from flying in the European Union over safety concerns.

The carrier has a fleet of 29 aircraft, including six ATR aircraft, according to FlightRadar24, a plane-tracking website. The ATR-72 that crashed Sunday had been built in 1993, Aseman Airlines CEO Ali Abedzadeh told state TV.

The plane took off from Tehran at 4.33am and gave its last signal at 5.55am, when the flight was at 16,975 feet and was descending, FlightRadar24 said.

HISTORY OF CRASHES

Aseman Airlines has suffered other major crashes with fatalities. In October 1994, a twin-propeller Fokker F-28 1000 commuter plane flown by the airline crashed near Natanz, 290 kilometres south of Tehran, also killing 66 people on board. An Aseman Airlines chartered flight in August 2008, flown by an Itek Air Boeing 737, crashed in Kyrgyzstan, killing 74 people.

Decades of international isolation have left Iran’s airlines with ageing fleets of passenger planes which they have struggled to maintain and modernise.

Aseman’s fleet includes at least three ATR-72s that date back to the early 1990s, according to the IRNA news agency.

A spokesman for ATR, which is part-owned by Europe’s Airbus, told AFP the company was “researching the details” of Sunday’s crash.

INVESTIGATION UNDERWAY

President Hassan Rouhani ordered the transport ministry to set up a crisis group to investigate the crash and co-ordinate rescue efforts, ISNA reported.

Aseman’s three Boeing 727-200s are almost as old as the country’s 1979 Islamic revolution, having made their first flights the following year.

Iran has suffered multiple aviation disasters, most recently in 2014 when a Sepahan Airlines plane crashed killing 39 people just after takeoff from Tehran, narrowly avoiding many more deaths when it plummeted near a busy market.

Lifting sanctions on aviation purchases was a key clause in the nuclear deal Iran signed with world powers in 2015.

Following the deal, Aseman Airlines finalised an agreement to buy 30 Boeing 737 MAX jets for $US3 billion ($3.8 billion) last June, with an option to buy 30 more.

However, the sale could be scuppered if US President Donald Trump chooses to reimpose sanctions in the coming months, as he has threatened to do.

Israeli Prime Minister Benjamin Netanyahu offered his condolences over Sunday’s crash, just moments after he launched a blistering attack on Tehran’s government.

“I take this opportunity to send condolences to the families of the 66 civilians that lost their lives,” Netanyahu said at the Munich Security Conference.

“We have no quarrel with the people of Iran, only with the regime that torments them,” he added.

The US Treasury Department, which must approve aviation sales to Iran, has done so for 80 Boeing jets destined for national carrier Iran Air as well as 100 Airbus planes for Iran Air.

The first few Airbus jets have already arrived in Tehran.