Thousands of people attending an official celebration in the southwest province of Sichuan spotted a UFO "slowly spinning" through the night sky, a Chinese report said Wednesday.

The sighting occurred around midnight May 17 over the Tibetan district of western Xiangcheng county following a heavy rain, according to the semiofficial China News Service.The UFO was sighted by a large crowd attending a night rally held to mark the 55th anniversary of the communist Red Army's passage through the region during the 1934-35 Long March, the report said.

"Thousands of people witnessed the UFO shining and moving forward in spirals for 11 minutes," the report said.

The unidentified object was described as "slowly spinning, flying from northwest to northeast."

Xiangcheng county borders Tibet and southwest Yunnan province.

The crew of a state-run commercial aircraft also reported spotting a UFO over south Sichuan on the same evening, 335 miles west of the mass sighting, according to the report.

There was no explanation for the dual sightings.