Over the months between Aug and Oct. 2015, more than 100 UFOs have been reported as seen along the India China border have left the officials puzzled.

It was reported that “yellowish spheres appear to take off from the horizon on the Chinese side and slowly travel across the sky for a few hours before they disappeared.”

Some officials added that these UFO sightings have puzzled the Indian military groups, including the air force, NTRO technical intelligence agency and the Indo-Tibetan Border Police.

Army officials who are in charge of the long border between India & China have reportedly ruled out Chinese drones or low-orbit satellites. Members of Indian Agencies  sent reports to their Delhi headquarters, describing the spheres as Unidentified Luminous Objects, or ULOs, whether they’re seen during the day or night. After carefully examining the hazy photographs of the ULOs, army officials ruled out unmanned aerial vehicles, reported India Today.

In September this year, the Indian army had brought a mobile ground-based radar unit and spectrum analyser to the top of a mountain near Pangong Lake between India and China. India Today reported that one of the ULO’s was spotted visually but it wasn’t picked up on the radar, which indicated it was non-metallic.

A team of astronomers from the Indian Astronomical Observatory at Hanle observed the ULOs for several days. Although they couldn’t figure out exactly what the objects were, they ruled out meteors and planets.

There have been reports of luminous objects reportedly seen on the Chinese side of the border, India Today reported. Even though scientists both in India and China aren’t sure what these ULOs are, they’re not ready to consider them visitors from another planet.

“There is no evidence of the UFOs being of extraterrestrial origin,” India Today quotes astrophysicist Jayant Narlikar. “The implication of them being alien objects is fancy, not fact.”