A preliminary report by Iran's military found no evidence of foul play or attack during the investigations into the helicopter crash that claimed the life of President Ebrahim Raisi, state media reported on Friday.

Raisi, a hardliner considered as a potential successor to Supreme Leader Ayatollah Ali Khamenei, died when his helicopter crashed in adverse weather conditions in the mountains near the Azerbaijan border on Sunday.

The report issued by the armed forces general staff stated that signs of gunshot or similar causes were not observed in the wreckage, which crashed in a high altitude area and subsequently burst into flames. Additionally, it mentioned that there were no suspicious elements in the control tower's conversations with the flight crew. Further details will be provided as the investigation progresses, the report added.

Raisi was laid to rest on Thursday, four days after the crash along with Foreign Minister Hossein Amirabdollahian and six others. Iran's poor air safety record, attributed to multiple crashes, especially involving US-built aircraft obtained prior to the 1979 Islamic revolution, has been highlighted by experts. Tehran has cited US sanctions as hindering the acquisition of new aircraft or spare parts from the West to modernize its aging fleets.

Iran announced a five-day mourning period for Raisi, known for implementing Khamenei's policies, suppressing public dissent, and adopting a firm stance on foreign policy, including negotiations with the US to revive the 2015 nuclear agreement. A presidential election has been scheduled for June 28.