At least 17 young people were found dead at a nightclub in a township in South Africa's southern city of East London on Sunday, police said.

“We got a report about 17 (people) that died in a local tavern in Scenery Park which is based in East London,” a provincial police chief brigadier Thembinkosi Kinana told AFP.

“We are still investigating the circumstances surrounding the incident,” he added.

He said the victims were aged between 18 and 20 years of age.

The Eastern Cape provincial community and safety department official Unathi Binqose, speaking from the scene, ruled out a stampede as cause of death.

“It's difficult to believe it's a stampede as there are no visible open wounds to those dead,” Binqose told AFP by telephone.

A regional local newspaper, DispatchLive, reported “bodies are lying strewn across tables, chairs and on the floor; with no obvious signs of injury”.

Unverified pictures shared on social media showed bodies with no visible signs of injuries, strewn on the floor of the club.

Local television showed police officers trying to calm down a crowd of parents and onlookers gathered outside the club in the city, which lies on the Indian Ocean coast, nearly 1,000km south of Johannesburg.

“Parents whose children did not sleep home are gathered here and they want to enter the tavern to look for their loved ones,” said Binqose.

He said he understood the patrons were students “celebrating pens down, a party held after writing (high school) exams”.