The helicopter carrying Iran’s late president Ebrahim Raisi caught fire soon after it crashed into a mountain and there was no sign it had been attacked, state media reported.
The statement from the general staff of the armed forces in charge of investigating the crash was read out on Iranian state television late on Thursday.
The broadcast did not apportion any blame over the incident but said more details would come after further investigations.
The crash on Sunday killed Mr Raisi as well as the country’s foreign minister and six other people.
The general staff’s statement said the communications between the control tower and the crew of the helicopter before the crash contained nothing suspicious.
It said the last communication of the crashed helicopter was between it and two helicopters which accompanied it some 90 seconds before the crash.
There was no sign anything had been fired at the helicopter and its flight path did not change, the statement said.
The aging Bell helicopter went down in a foggy, remote mountainous region of north-west Iran on Sunday.
The crash site was discovered on Monday morning with all eight on board dead.
Mr Raisi was buried in a tomb at the Imam Reza Shrine in Mashhad on Thursday.
