Iranian spiritual leader Seyyed Ali Khamenei on Saturday ordered an investigation into the likely negligence or faulty performance in the air disaster case.

The Supreme Leader instructed the General Chief of Staff of the Armed Forces to take necessary measures to probe the incident and make sure such events will not be repeated.

Sympathizing with the bereaved families of the air disaster, Ayatollah Khamenei said after being informed of the results of the investigation by General Staff of the Armed Forces which indicated a human error in the plane crash, he felt the sorrow even deeper than before, IRNA reported.

Earlier Iranian president Hassan Rouhani said those responsible for the plane crash would be held accountable.

“The Islamic Republic of Iran is deeply sorry by this disastrous mistake, and I extend my deepest condolences to the families of the victims of this tragic incident on behalf of the Islamic Republic of Iran and instruct all related organs to take all necessary measures to compensate and sympathize with the bereaved families,” he said in a statement.