An unexplained explosion in South Africa’s largest city Johannesburg cracked open a road and sent cars flying.

The explosion took place in Johannesburg’s Bree Street in the Central Business District. Authorities have so far not been able to determine the cause.

A CCTV video showed a an explosion that bumbed the road up in the air, causing the tarmac top to crack and sending vehicles flying. People on the roadside scrambled to safety.

Photos from the aftermath of the explosion showed a large crack down the middle of the road as well as vehicles stranded in a damged condition. A large hole appeared at one spot in the road as well.

A disaster management team has cordoned off a 1km part of the road due to risk of further accidents.

Authorities said that no deaths were reported in the incident. However, many people had to be resuced from their vehicles and 11 people were said to be injured.

Initial reports said that the explosion could have been caused by a gas leak and some locals even reported a smell.

However, Egoli Gas, the company that manages the gas pipeline underneath the road denied that any damage had been made to their infrastrucutre. It added that the pipeline installed under the road were built to one side and that no loss of pressure had been reported.