A driver who may have been blinded by the sun has run into a group of cyclists at West End, in inner-city Brisbane, injuring five people, including one who has critical head injuries, paramedics say.

It is believed the car was travelling uphill at Dornoch Terrace about 6:20am and pulled into a driveway to do a U-turn when the cyclists came down the hill.

The cyclists, aged between 45 and 55, have suffered injuries including broken bones and concussion, paramedics said.

Five riders were injured by the car on Dornoch Terrace. ( Facebook: Julian Drake )

The 45-year-old in the group has critical head injuries and was taken to the Princess Alexandra Hospital.

The four others were transported to the Royal Brisbane and Women's Hospital.

Cyclist Tom Nash, who was part of the group, said it was a "complete disaster" and there had been bikes and bodies everywhere, with some bikes broken in two.

A cyclist is in a serious condition and four others have suffered significant injuries. ( ABC News: Isobel Roe )

He said the cyclists had been riding in a group together for about seven years.

"We leave Park Road at about 5:15 in the morning, this is our regular route, we come down Dornoch Terrace every Friday and this unfortunate accident has happened," Mr Nash said.

He said he was ahead of the group and escaped the crash, but circled back when he realised what happened.

A mangled bike after being hit by the car. ( Facebook: Julian Drake )

"I just saw an absolute mess," he said.

"We had five of our riders hit by a car, none of them were in a good way at all, so I just hope they're all OK."

'Car looks like it's been hit by another car'

Cyclist David Shelberg also escaped injury but said his wife was one of those injured and taken to hospital.

He said he thought she had not been seriously injured, but others might have fared worse.

"I think there's going to be some pretty bad ones … that car looks like it's been hit by another car," he said.

"I was in front of it."

The driver of the car remained at the scene, with paramedics saying it was believed the person was blinded by the sun. ( ABC News: Isobel Roe )

Dornoch Terrace is part of the River Loop, a cycling route followed by hundreds of recreational cyclists every week which goes from Coronation Drive through St Lucia to Indooroopilly, the riverside suburbs and Highgate Hill before descending Dornoch Terrace into West End.

Friday is the most popular day for the trip.

Queensland Ambulance Service spokesman Matt Davis said "potentially the angle of the sun may have come into play" in today's incident.

Mr Nash said they had set off about 5:15am on their regular route when the disaster struck an hour later. ( ABC News )

"What we do know is the car was essentially turning out onto the road and didn't have visibility of the cyclists.

"So that's, we're assuming, what's resulted in the accident."

Mr Davis said it was quite fortunate no-one was killed.

"They've all been exceptionally lucky, certainly given the mechanism involved, and of course we have high concerns for any cyclist who's been struck by a car," he said.

Police investigations are underway.

Site common for crashes

Bicycle Queensland chief executive Ben Wilson said there was a bicycle lane on much of the popular cycling route road, but there was no dedicated lane where the crash happened.

Paramedic Matt Davis said it was lucky no-one died. ( ABC News: Isobel Roe )

He said Dornoch Terrace was on one of the busiest cycling routes in Brisbane, with the crash hitting a nerve in their community.

"It's in the top five [crash sites] in the state," Mr Wilson said.

"We've got to look at roads like Dornoch Terrace and look at its function and improve it for everybody."

The RACQ's Lauren Ritchie said she would encourage a review of safety on that stretch of road.

"We've seen around six incidents where there was some injuries to a cyclist in the last 10 years, basically 100 metres from this exact location, so it is a high-risk area," she said.

"The safest infrastructure for cyclists and motorists is to have ... a separate path."