Three Britons have died after a Ukrainian passenger plane crashed moments after take off from Iran, officials have said.
All 167 passengers and nine crew on the Ukraine International Airlines Boeing 737 flight from Imam Khomeini International Airport in Tehran to the Ukrainian capital Kiev were killed minutes after take-off at 6.10am local time (2.40am GMT) on Wednesday.
The crash comes amid escalating tensions in the Persian Gulf following the killing last week of Iranian General Qassem Soleimani by the US.
But Qassem Biniaz, a spokesman for Iran's Road and Transportation Ministry, said it appeared that a fire had started in one of the plane's engines.
The pilot then lost control of the plane, sending it crashing into the ground, Mr Biniaz said, according to the state-run IRNA news agency.
Some 82 Iranians, 63 Canadians, 11 people from the Ukraine, nine of whom were crew members, 10 Swedes, four Afghans and three Germans were on board the flight along with three Britons, Ukrainian Foreign Minister Vadym Prystaiko said.
He said: "Terrible news about the plane crash in Tehran. My sincere condolences to the families of the dead."
Rescue crews said they did not expect to find survivors.
The airline said it had suspended flights to Tehran until further notice.
A spokesman said: "Today, on January 8, 2020, a Ukraine International Airlines aircraft while operating flight PS752 from Tehran to Kyiv disappeared from the radars a few minutes after departure from Tehran International Airport.
"The aircraft departed from Tehran International Airport at 06:10hrs. Iran local time.
"According to preliminary data, there were 167 passengers and 9 crew members on board.
"UIA representatives are currently clarifying the exact number of passengers on board.
"The airline expresses its deepest condolences to the families of the victims of the air crash and will do everything possible to support the relatives of the victims.
"With immediate effect, UIA has decided to suspend its flights to Tehran until further notice."
The airline said the aircraft was a 737-800, built in 2016.
A number of 737-800 models have been involved in deadly accidents over the years.
In March 2016, a FlyDubai 737-800 from Dubai crashed while trying to land at Rostov-on-Don airport in Russia, killing 62.
A 737-800 flight from Dubai, operated by Air India Express, crashed in May 2010 while trying to land in Mangalore, India, killing more than 150 people.
However, it is a different model to the Boeing 737 Max 8 jets, which were grounded around the world following the crash of an Ethiopian Airlines plane that killed 157 people shortly after take off from Addis Ababa in March last year.