Iran’s state news agency called the crash of the presidential helicopter a `technical problem` while the military has not announced the conclusion of the investigation.

Two news reports about the late Iranian president Ebrahim Raisi and the late foreign minister Hossein Amirabdollahian, posted on May 20 on the website of the state news agency IRNA, both described them as having died `in a helicopter crash due to an accident.`

The statement did not specifically describe the technical problem that occurred during the May 19 flight.

Iranian Army Chief of Staff Mohammad Bagheri appointed Brigadier General Ali Abdollahi, deputy chief of staff of the army, to the scene with a team of experts and technicians to investigate the cause of the tragedy.

Previously, former Iranian foreign minister Mohammad Javad Zarif also hinted that the plane’s quality was not guaranteed.

The helicopter carrying President Ebrahim Raisi broke down and burned on a mountainside, with the tail broken off in East Azerbaijan province, northwestern Iran on May 20.

The Bell 212 helicopter crashed while carrying 9 people including President Raisi, Foreign Minister Hossein Amir-Abdollahian, Governor of East Azerbaijan Province Malek Rahmati, cleric Mohammad Ali Ale-Hashem, the presidential guard group and three returning pilots.

Some aviation experts believe that the helicopter carrying Mr. Raisi may have had a sudden and serious technical problem, to the point that the pilot did not have time to radio with air traffic control or the two helicopters moved at the same time.

The Bell 212 helicopter was developed by the US in the late 1960s and sold to many countries around the world, including Iran before the Islamic Revolution broke out in 1979. Iran currently has to rely on domestic resources for maintenance.

Iran’s aviation industry used to be very developed until the United States began imposing sanctions in 1995, preventing the Middle Eastern country from modernizing its passenger aircraft fleet for Iran Air.

When the nuclear monitoring agreement was signed in 2015, the US relaxed some sanctions targeting Iranian aviation.

`Iran has recorded many aviation incidents, including helicopter and plane crashes. The connection between this situation and sanctions is very clear,` Sanam Vakil, Middle East expert at the organization

Meanwhile, when asked about former Secretary of State Javad Zarif’s comments, the US State Department said that the Iranian government was responsible for the accident when deciding to let the 45-year-old helicopter fly in bad weather conditions.