Visitors looking at the bears. (Newsflash)

A busload of visitors to a Chinese wildlife park have watched on in horror as a zookeeper was fatally mauled by a pack of bears on the weekend.

The gruesome accident took place at the Shanghai Wildlife Park on Saturday (local time) in the zoo’s “wild beast area”, the BBC reported.

Video of the attack was shared on Chinese social media site Weibo, reportedly showing tourists watching on as the zookeeper was mauled by the animals.

According to the BBC, a male passenger can be heard alerting others to the presence of the zookeeper, exclaiming “there’s someone [there]” while another passenger is heard asking “what’s going on?”.

While the zookeeper was being mauled a nearby worker operating an excavator tried to drive the bears away, but was unable to. The operator remained in the vehicle while the bears dragged the victim’s body to a quieter spot, and he waited for the police to arrive.

The video went viral on Weibo and sparked debate about the existence of zoos as some Chinese users argued the wild animals just did what comes naturally to them.

According to its website, the Shanghai park boasts “more than 10,000 exotic animals of more than 200 species, most of which are rare wildlife, including giant pandas, snub-nosed monkeys, takins, crested ibis, white rhinos, cheetahs, giraffes, zebras and antelopes.”

The park is divided into a drive-through section, pedestrian area and a water-based section.

In drive-through area, animals live in their nature habitat, while humans are kept in a ‘cage’, the zoo’s website says. Source: Shanghai Wildlife Park

The zoo has expressed condolences to the family of the zookeeper and has promised to improve its safety protocols following an investigation, saying it has since closed the “wild beast” area where the attack occurred.

“Our park is extremely saddened by such a tragedy, expressing deep condolences to the deceased, expressing deep sympathy to the families of the deceased, and apologising for the inconvenience it caused to tourists,” the park said in a statement.

“At present, our park is actively cooperating with relevant departments to conduct an incident investigation.”

According to Chinese state media, witnesses to the attack were offered a refund on their tickets.