The helicopter carrying Iran's late President Ebrahim Raisi caught fire soon after it crashed into a mountain and there was no sign it was attacked, state media reported, citing the military's crash investigators.

The statement from the general staff of the armed forces in charge of investigating the crash was read on state television late Thursday. The first statement on the crash did not lay blame but said more details would come after further investigation.

The crash Sunday killed Raisi, 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 accompanying it some 90 seconds before the crash.

There was no sign of anything shot 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 Iran's northwest on Sunday. The crash site was discovered Monday morning with all eight on board dead.

Raisi was buried in a tomb at the Imam Reza Shrine in Mashhad on Thursday.