The Beijing Center for Disease Control and Prevention confirmed that a video, posted online, of insects on a train bunk are bugs, Xinhua News Agency reported on Monday.

A passenger filmed the bugs on a D313 high-speed train a few weeks ago between Beijing and Shanghai and uploaded videos of a sheet with small insects.

Zeng Xiaopeng, deputy director of the Beijing CDC, confirmed that they were bugs.

On Aug 7, the center issued a warning about bug infestation and said the public should use pesticide or report any findings to the appropriate services.

Bugs have been largely absent over the last three decades but appear to be coming back, possibly because of the high number of overseas travelers, said Zeng.