Chaotic scenes erupted after a vigil exploded into all-out violence with cars torched and hordes of people chanting and squaring up to police.
A throng of people were seen chanting and cheering on Thursday night as a car was pushed down a steep hill into bollards while another vehicle was set ablaze.
Photos showed two cars on fire in the middle of the street surrounded by smoke while the crowds thronged around them.
In another video people were seen hurling objects and shouting at retreating police using riot shields.
One eyewitness claimed there was about 200 people at the disturbance which began at around 8pm, Wales Online reports.
Officers warned people to stay indoors amid the shocking scenes on the streets of Swansea's Mayhill area on Thursday night.
Images and footage posted on social media showed cars on fire in the middle of the road and crowds cheering as a vehicle was rolled down a hill.
Speaking to Wales Online a dad-of-two described the moment wanton rioters put his windows through and hurled bricks at him after torching his car.
Uber Eats driver Adam Romain said there was “literally a riot” on the doorstep of his home in Mayhill, Swansea, on Thursday night as his terrified family cowered inside.
Adam said: “I’ve had a phone call from my girlfriend saying that there was a riot essentially going on outside, cars being burnt. I understood that it was my car – it was all said very quickly.
“I shot back as quickly as I could – I was out doing deliveries. I came back as quick as I could and drove up right into the middle of it. About 100 lads throwing bricks, burning up cars. I stood here, put my motorbike inside the house, was trying to protect it, and was stood here trying to protect my home, my family, my children, and my missus was in the back hysterical, crying, scared to death.
“They’ve tried to light this car on fire. They’ve taken a bumper off another car and it’s been thrown in there and then they’ve run back up the hill. As soon as they’ve left I’ve gone outside and tried to stop it from catching fire."
Video footage from the scene appeared to show a mob attacking, kicking and hurling objects at a police van as it attempts to leave the scene.
The crowd can be seen violently attacking the van as it reverses away slowly.
Other videos showed officers in riot gear and shields having things thrown at them as people scream, laugh and film it.
As one man picks up what looks like a stone or a brick, someone shouts "Put it through!" before hurling it at the police van.
A large crate is also thrown at the van's windscreen. As the van reverses, people can be heard screaming in encouragement of the attacks on the van.
Local Welsh Parliament member Tom Giffard called the scenes "disturbing".
Welsh secretary and Carmarthen West and South Pembrokeshire MP Simon Hart said: "A tough night for the police dealing with such reckless behaviour.
"No excuses, police right to robustly respond."
South Wales Police Superintendent Tim Morgan said that what was believed to have started as a vigil for a recently-deceased local resident had escalated into "violence, criminal damage and a wanton disregard for public safety".
He added: "We have a number of officers at the scene working to de-escalate the situation as quickly as possible and allow other emergency service colleagues to attend to calls in the area.
"The incident is still on-going and we urge anyone involved to leave the scene immediately.
"Those involved can expect to face robust action. Post-incident investigations will also aim to identify all those concerned.
"In the meantime, we urge local residents to stay indoors while the matter is brought to a safe conclusion."
