Two teenagers who died in a crash which sparked a riot in Cardiff have been named locally as Kyrees Sullivan, 16, and Harvey Evans, 15, the BBC has been told.
The boys were killed while riding an electric bike in Ely shortly after 18:00 BST on Monday.
Some residents claimed to the PA news agency that the boys were being chased by police.
South Wales Police denied that the boys were being pursued.
Cars were set alight and fireworks thrown at police as more than 100 people gathered following the crash.
Bridy Bool, who knows the family of Harvey, said he had "loads of friends" and loved motorbikes and football.
"He was best friends with Kyrees and [they] were into the same things. It was not unusual for them to be together," she said.
Ms Bool said she believed the pair were being chased by officers "as there are videos going around".
Police dismissed this claim and said they arrived at the scene after the crash, remaining there to manage "large-scale disorder" until the early hours of Tuesday.
Up to 12 officers were injured in the rioting, said South Wales Police and Crime Commissioner Alun Michael.
"It would appear that there were rumours, and those rumours became rife, of a police chase - which wasn't the case," Mr Michael said.
South Wales Police said arrests had been made but did not say how many.
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Cars were set alight and fireworks thrown at police as 100 to 150 people gathered in Ely on Monday night.
At about 20:00, police tweeted that they were still at the scene of the collision but were also working to "de-escalate ongoing disorder".
The force said it had received a large number of calls from "understandably frightened" residents.
By 01:10 BST on Tuesday, police said a number of vehicles had been set alight and arrests were being made.
The force said its thoughts were with the families of the boys who died as well as those affected by the rioting.
More arrests would follow, a police spokesperson said.
Mr Michael told BBC Radio 4's Today the crash was "being investigated in its own right", but that it appeared to have sparked the disorder.
He said the connection between the two events was "far from clear".
"There's going to be investigations going on this morning to try and establish what happened," Mr Michael said.
"Our focus now is to fully investigate the circumstances of the collision and the appalling scenes that followed", the spokesperson added.
First Minister Mark Drakeford - whose Cardiff West constituency includes Ely - said he was "very concerned" by the "upsetting reports".
Prime Minister Rishi Sunak's spokesperson said what had happened was "appalling and completely unacceptable".
The IOPC said: "We have not received a referral from South Wales Police with regards to the incident in Ely last night and there is no indication yet that we will receive a referral."
https://www.bbc.co.uk/news/uk-wales-65685293
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