A Ukrainian commercial airliner crashed on January 8 soon after taking off from Iran’s capital, Tehran, killing all 176 people on board, mostly Iranian nationals, but also Western and Ukrainian citizens.

The Boeing 737-800 belonging to Ukraine International Airlines (UIA) had taken off from Imam Khomeini International Airport in Tehran when a fire struck one of its engines, according to Qasem Biniaz, a spokesman for Iran’s Road and Transportation Ministry.

The pilot of the aircraft then lost control of the plane and it crashed, Biniaz told state-run IRNA news agency.

Ukrainian Foreign Minister Vadym Prystayko said 82 Iranian citizens were on board, as well as 63 Canadians, 10 Swedes, four Afghans, three Germans, and three Britons.

Ukraine’s Security Council said 11 Ukrainians were also killed in the crash, including nine crew members.

President Volodymyr Zelenskiy said in a statement that he had instructed the country’s prosecutor-general to open criminal proceedings over the crash. Zelenskiy said the airworthiness of Ukraine’s entire civilian fleet will be tested.

“My sincere condolences to the relatives and friends of all passengers and crew,” Zelenskiy said, announcing that he was breaking off his visit to Oman to return to Kyiv.

Ukraine International Airlines said that it was doing everything possible to find out the causes of the crash and would undertake a thorough investigation.

Zelensky has also reportedly instructed the country’s prosecutor general to open criminal proceedings over the air crash, according to Reuters.