People in a village in Shaanxi province, China, were confused when they encountered a mysterious object falling from the sky into the mountain, creating a large burning crater on the ground.

Villagers of Zhangjiapan in Shaanxi Province, China said they heard a loud explosion and saw an object falling to the top of the mountain, People’s Daily Online reported on December 15.

People flocking to the scene discovered a burning crater 0.9 meters long, nearly 0.6 meters wide with deformed metal pieces. The fire was extinguished and there were no reports of injuries.

A piece of metal was found inside the crater. Video taken by witnesses showed a fire burning in the middle of a large crater.

A man named Zhang said he heard an explosion around 1 p.m. on December 9 and witnessed an object falling.

“It made a loud explosion when it landed. Then it started to burn. The dry grass nearby quickly caught fire,” Zhang said.

A metal disk-shaped fragment with many rivets was found by people at the scene.

According to HSW.cn, police found debris that may be related to the incident in three locations in the southwestern part of Fugu district. The debris that fell near the crater was a large metal circle with many letters and numbers on its surface.

The incident attracted much speculation on China’s QQ social network. Some people believe that the object fell from an alien spacecraft, while many people claim that this is a fragment of a satellite or rocket that fell to the ground. Police are investigating the incident and all three pieces of debris have been examined.