Motorists were injured and a petrol bomb was hurled at a vehicle on the N2 outside Cape Town on Sunday night as protesters wreaked havoc stoning cars.

Two people were hospitalised after stones pelted their vehicles about 6:30pm while a petrol bomb caused minor damage to a third vehicle, with protesters burning tyres alongside the road.  

The road was closed in both directions from Broadlands to Onverwacht. The cause of the protest was not immediately clear.

DJ Nino Deep witnessed the violence first hand, writing his account of events on Twitter and Facebook shortly afterwards.

"Thank God we safe and wasn't hurt as our car and other motorists [fell] victim to a protest on being stoned just a moment ago on the N2 just before Somerset West," he wrote on Facebook. 

"... We managed to get to home safe and car has minimal damage. Just one passenger window and the windscreen.

"My heart goes out to the couple who was in front us. I pray to God and hope they managed to get to safety as their car was set alight with a petrol bomb."

Nino said the experience was "too traumatic to relive" when contacted by our sister publication TimesLIVE on Monday. 

Cape Town law enforcement spokesperson Wayne Dyason said that no arrests had been made, as the crowd quickly dispersed when police arrived.