The unidentified flying object, spotted in several cities in China by netizens this week, was probably a high-altitude government sounding rocket from a scientific experiment, according to an institute of the Chinese Academy of Sciences.

The National Space Science Center, under the CAS, said on its website on May 14 that it successfully conducted a test of a high-altitude sounding rocket at 9 pm on May 13, which was launched from the Xichang Satellite Launch Center in Sichuan province.

A sounding rocket is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight.

According to the National Space Science Center, the scientific experiment on May 13 had obtained firsthand data of space environment in different altitudes, which will be important for China's space environment monitoring.

Witnesses had released pictures of the rocket-like object, spotted in several cities in South China and Southwest China, which became a hot topic online.