Terrified workers fled a skyscraper in China after it began wobbling without explanation.
The Shenzhen Emergency Management Bureau said it had received reports the SEG Plaza was wobbling and was investigating.
It said there had not been an earthquake when the shaking took place around 1.50pm on Tuesday and the local weather report showed a wind speed of around 27km per hour - a force unlikely to cause shaking.
"After checking and analysing the data of various earthquake monitoring stations across the city, there was no earthquake in Shenzhen today," a statement on Chinese social media said. "The cause of the shaking is being verified by various departments."
Chen Wei, a worker at the SEG Electronics Market attached to the SEG Plaza, told the South China Morning Post he had not felt any shaking but was told to leave the building with others.
“One of my friends was in the [high rise] building and noticed that the water bottles on the desk started to shake,” he said.
Mr Chen said nearby buildings were evacuated and nearby roads temporarily blocked.
Lu Jianxin, a chief engineer at China Construction Science and Industry Corp, told local newspaper Shenzhen Special Zone Daily that the shaking could have been caused by “resonance” effects.
“If there was no earthquake today, it would be unusual for SEG Plaza to have such a situation,” they said. “Judging from the currently available information, this could be an accidental frequency coincidence, that is, resonance.”
The tower, which stands at a similar height to the Empire State Building in New York City, hosts a major electronics market and various offices.