The police officers pursuing two teenagers riding an electric bike minutes before they were killed in a crash were the first to arrive at the scene of the collision, a senior police chief has confirmed.

Harvey Evans, 15, died alongside his best friend Kyrees Sullivan, 16, when the Sur-Ron bike they were riding crashed in the Ely area of Cardiff on Monday evening.

Their deaths sparked rioting after video footage of a marked police van following the teenagers quickly circulated on social media.

South Wales Police said the collision had already occurred when the first officers arrived at the scene in Snowden Road.

Alun Michael, the local Police and Crime Commissioner, said he had been “assured and I am still assured youths were not being chased by the police at the time of the road traffic accident”.

Cardiff road traffic collision
Harvey Evans, 15, (right) died in the crash (Family handout/PA)

Deputy Chief Constable Rachel Bacon said the police van, which had been following the boys, was the first to respond to the collision.

“Our thoughts are with the families and friends of Kyrees and Harvey and everyone affected by this terrible incident,” she told a press conference.

“We can only begin to imagine the grief they are experiencing at this time. The families continue to be supported and updated by family liaison officers.”

She told reporters the pursuit began on Frank Road when the bike turned around after seeing the police van and was then followed by the officers who did not turn on their lights or sirens.

They turned into Stanway Road, which is closed to traffic at one end, and local residents believe Harvey and Kyrees carried on to pass through the bollards to avoid the police – forcing officers to turn into Howell Road and onto Grand Avenue to loop around the estate.

Ms Bacon said that at the time of the collision the van was in Grand Avenue – half a mile away from Snowden Road – and when officers learned of the collision they were on Cowbridge Road West and turned on their blue lights and headed to the scene.

Cardiff road traffic collision
Kyrees Sullivan died in the collision with his best friend Harvey Evans (Family handout/PA)

“There was no police vehicle in Snowden Road at the time of the collision and we believe there were no other vehicles involved in the incident,” she said.

“We have made a mandatory referral to the Independent Office for Police Conduct to ensure the matter receives independent scrutiny.

“We will provide them with all the information we have, and they will undertake an independent investigation.”

Ms Bacon confirmed no police officers have been questioned under caution since the incident.

“It didn’t go as any of us would have wanted on the night of the incident. It is a tragic outcome that two young men have died and we want to understand why,” she said.

Cardiff road traffic collision
Deputy Chief Constable Rachel Bacon of South Wales Police speaks to the media at a press conference at the force’s HQ in Bridgend (Bronwen Weatherby/PA)

Meanwhile, the family of Harvey Evans pleaded for “peace within the community” as they paid tribute to “our much-loved son, grandson, brother, nephew, friend and boyfriend”.

They said in a statement: “He lived life to the full, he had a big heart and deep down he truly cared. He was a best friend to Kyrees and our thoughts and prayers are with his family also.

“We ask for peace within the community and request that people leave the investigation to the police so we can get the answers we so desperately need to lay Harvey to rest.”

Kyrees Sullivan’s family also paid tribute and thanked the local community for their support since his death.

“Kyrees was a loving, caring, handsome young man, a loving son to Belinda and Craig, little brother to Aleah and Jordan and a special uncle KyKy to Myra,” they said.

“He was loved so much by his grandparents and aunties and uncles, and his many cousins.

The scene in Ely following the riot
The scene in Ely following the riot (PA)

“Him and Harvey along with Niall were best friends since they were young and went everywhere together, they both had so many friends and were very well liked doing many things together, having fun and laughs.”

Hundreds of bunches of flowers have now been placed at the scene and floral tributes have also been taped the entire length up one lamppost on the street.

Community members and young people continue to gather at the scene and say there is still a strong feeling of anger at the police among those who knew the teenagers and their families.

One young man at the scene who came to pay his respects said: “They (the police) are trying to hide what really happened. The video is as clear as day.”

A woman at the tributes, who did not give her name, told journalists that “young people are always targeted by police around here”.

A vigil and balloon release has been planned to pay tribute to the boys on Friday evening.