A Boeing 737-800 passenger jet operated by Ukranian International Airlines has crashed shortly after take-off from Tehran, Iran, killing all 176 people on board.

Taking off from Tehran’s Imam Khomeini International Airport, the Kyiv-bound aircraft is reported to have crashed at 6:22am local time.

The reason for the crash is yet to be ascertained. Iran’s Fars news agency reported that technical problems could be the potential cause of the crash.

The incident is believed to bring an additional crisis for Boeing, which has been trying to recover from two crashes in a span of five months.

Boeing grounded the 737 Max in March 2019 after the jet was involved in the crashes, which took place in October 2018 and March 2019.

Ukrainian Airlines received the crashed 737-800 jet in 2016, according to Flightradar24.

Meanwhile, Boeing has recommended that 737 Max pilots undergo simulated training before flying the aircraft.

In a statement, the company said: “This recommendation takes into account our unstinting commitment to the safe return of service, as well as changes to the airplane and test results. The final determination will be established by the regulators.”

The recommendation marks a shift for the company, which earlier was promoting for computer-based pilot training, reported CNBC.