Rescuers are still trying to find the exact location where a helicopter carrying Iranian president Ebrahim Raisi crashed near the border with Azerbaijan on Sunday, but according to one official, contact has been made with a passenger and a member of the crew “several times,” CNN reports. Details were scant, but state TV said the incident happened near the border with Azerbaijan, in a mountainous forest region northwest of Tehran. State-run news agency IRNA, which initially described the incident as a “hard landing,” said response teams were hampered by poor weather conditions, including thick fog over the muddy terrain where the chopper went down. Raisi was returning from a diplomatic visit to Azerbaijan on Sunday morning when the crash occurred. An Iranian official told Reuters that the information coming from the rescue effort was “very concerning,” although there was no information available on Raisi’s condition. Iranian Vice President for Executive Affairs Mohsen Mansouri, however, told the state-affiliated news agency FARS that authorities had been in contact with at least two others who had been aboard the flight—leading him to believe that the incident was “not severe,” according to CNN. The president is a favorite of Iran’s Supreme Leader and is seen by some analysts as a possible successor. Most of Iran’s military aircraft are several decades old, the AP reported, and it’s often difficult to replace parts because of international sanctions.