Residents of the Chinese city of Shenzhen, adjacent to Hong Kong in the southern province of Guangdong, noticed mysterious spots of colour appearing between the clouds in the night sky on 25 July.
A local meteorological bureau uploaded a video of the mysterious lights in Shenzhen's sky to the Chinese social network Weibo.
Some internet users assumed that it could be UFOs flying in the sky.
The lights had red, green and yellow hues.
However, experts from the local meteorological bureau have identified the atmospheric phenomenon as light pillars, which usually take place in much colder climates.
"We call these 'warm evening light pillars'. They form in strict conditions (and are) even more particular than regular light pillars,” the meteorological bureau said.