A 16-year-old cyclist from Victoria, B.C. has died en route from Vancouver to Seattle after he was hit by a car during a 200-kilometre bike ride for charity, police said.

The teen was riding in the event with his uncle when he was killed shortly after 10 a.m. PT on Sunday near Arlington, about 80 kilometres north of Seattle.

Arlington Police told CBC News a group of cyclists was travelling together on a narrow stretch of road when the young rider tried to pass.

He clipped another bicycle and fell into oncoming traffic.

2,600 cyclists participated in the Ride to Conquer this weekend. (CBC)

The car that struck the boy was driven by a 50-year-old Arlington woman, police said. She was driving below the speed limit and is co-operating with the authorities.

Cyclists were diverted around the scene on an alternate route as police were on scene carrying out their investigation.

"All who are associated with The Ride to Conquer Cancer have been deeply saddened by this news and our thoughts and prayers are with family and friends of the rider," said Doug Nelson, president and CEO of the BC Cancer Foundation.

BC Cancer Foundation spokesman Eric Dierks says nothing like this has ever happened before on the ride.

"This has never occurred, nothing to this scale has every happened," he said. "There is some risk ... [but] nothing that comes near to this tragic news."

Cyclists react

Fellow rider Joe Graves said it was hard to keep riding after hearing about the young cyclist's death.

"It kind of takes the glow off the day," Graves said. "My kid's been battling cancer since five, he's 23, so you kind of focus on that."

On Saturday, more than 2,600 cyclists set off from Surrey's Cloverdale Fairgrounds on a 200-kilometre trek to Seattle.

Since the event began in 2008, more than $50 million has been raised, making it the largest cycling fundraiser in the province's history.

This year, participants raised $10.4 million to support research at the BC Cancer Agency.