1976 Tehran Pilot UFO incident

The Tehran UFO incident involved a visual sighting of a flying object over the capital of Iran, Tehran. It happened on 19th September 1976 and when the incident happened, two phantom jet interceptors lost communication and one of the members also reported that they experienced a weapon malfunction at the time of firing as well. The incident is reported in a US DIA document and it was sent to the White House, the NSA, the Secretary of State and the Joint Chiefs of Staff. The case itself remains to be one of the most well documented paranormal events of that time.
So what happened exactly?

The Iranian Air Force received four different reports that stated that they could see a bright object in the sky. General Yousefi went out and took a look for himself at the control tower, but he confirmed that it could not have been a star as this light was much brighter. He went out and after the incident happened, he went on to retire, asking the entire air force to investigate this properly. There was also a radiation test done to see if anything could explain the intensity of the light, however the results were never released. According to General Yousefi, the lights alternated between blue, red, green and orange and in the shape of a square; however this happened so fast that it was possible for them to be seen as one. The DIA report contained enough supporting information in order for it to quality for a valid study of a UFO encounter, yet nothing more has been heard on the matter.
– The UFO was seen by multiple people
-The witnesses were credible
– The sightings were confirmed via radar
-The aircraft was affected by electromagnetic effects
-The crew members experienced loss of night vision due to the bright lights
-The UFO’s movement was inordinate
Can this be explained? Or is it true what General Yousefi says, that this was an encounter from those not of this world?