Chinese authorities are conducting an investigation after 15 boxes filled with live snakes were found on a bus, according to local media reports on Saturday. The snakes were packed in boxes alongside containers that held toads and rats in the luggage compartment of a bus in the central Hubei province, according to a Xinhua report cited by Agence France-Presse.

Upon discovering the animals, many of the 53 passengers were “terrified” and ran away from the bus, which was 124 miles into its journey at the time.

The transportation of live animals in China must be approved by the country's transportation and quarantine authorities. Xinhua reported that the bus driver failed to produce the authorizing certificates.

China’s snake trade has drawn international condemnation, where the animal’s venom is drained for use in traditional medicine, their meat for cuisine and their skin for fashion accessories. “Because of their slow metabolism, many snakes suffer for hours or even days until they finally die [after being flayed],” PETA Asia representative Hailey Chang told local news site Beijinger. “Others slowly suffocate to death.”