Preliminary report says no evidence of criminal activity but investigators signal the probe is not yet over.

A preliminary report on the crash by the general staff of the armed forces said the craft had “caught fire after hitting an elevated area”, finding no traces of “bullet holes” on the helicopter wreckage, according to the official IRNA news agency late on Thursday.

The report also stated that Raisi’s helicopter had been flying on a “pre-planned route and did not leave the designated flight path” before the crash on Sunday.

“No suspicious content was observed during the communications between the watch tower and the flight crew,” it added.

The final communication between the president’s craft and two accompanying helicopters was recorded about a minute and a half before the crash, according to a statement from the general staff of the armed forces, broadcast on state television on Thursday night.

The helicopter wreckage had been found in Iran’s mountainous northwest by Iranian drones early on Monday, with the “complexity of the area, fog and low temperature” hindering the work of search and rescue teams.

However, while the first statement on the crash did not lay blame, it said that more details would follow. More time was needed, the army said, to conduct investigations.

Ageing helicopter

The ageing Bell helicopter that crashed was carrying Raisi and his entourage home from a trip to Iran’s border with Azerbaijan on Sunday.

The president had earlier inaugurated a dam project with Azerbaijani President Ilham Aliyev.

Foreign sanctions on Iran dating back to the 1979 revolution, and subsequently imposed over its nuclear programme and its backing of the so-called “axis of resistance”, have made it difficult for the country to obtain aircraft parts or new aircraft.

Raisi was laid to rest in his hometown of Mashhad on Thursday, concluding days of funeral ceremonies in some of Iran’s major cities including the capital attended by throngs of mourners.

Among the people killed in the incident was Iran’s Foreign Minister Hossein Amirabdollahian who was also buried on Thursday in the town of Shahr-e Ray, south of the capital.

A presidential election has been scheduled for June 28.