Protesters screamed and scattered as the car approached, 24-year-old Summer Taylor was killed, Diaz Love injured.
Several cyclists have been critically injured when a man in a pick-up truck ploughed into them during a community road race in the US state of Arizona.
Six people were taken to a hospital in critical condition after the crash on Saturday in the mountain town of Show Low, a three-hour drive northeast of Phoenix, police said.
The suspect, a 35-year-old man, also was hospitalised after he was shot by police and is in critical but stable condition.
Helmets, shoes and crumpled bicycles were strewn across the street after the crash, a tyre wedged into the grill of the truck, which had damage to its top and sides and a bullet hole in a window.
Two other people went to a hospital themselves, city spokesperson Grace Payne said. One of the severely injured was later flown by medical helicopter to a Phoenix-area hospital.
“We don’t know the motivation,” Payne told The Associated Press. “We know he fled the scene.”
Police said the pick-up truck struck the bicyclists at about 7:25am (14:25 GMT) during the annual 93km (58-mile) Bike the Bluff race before fleeing.
Officers pursued the driver and tried to stop him before he was shot, authorities said.
Tony Quinones, 55, of Santa Fe, New Mexico, told the New York Times that he had been riding for about six minutes with other cyclists ages 55 and over when a black pick-up truck that had been driving in the opposite direction crossed over three lanes and headed towards the cyclists.
He assumed the driver was turning into a parking lot. Instead, the driver ploughed directly into the cyclists who had been ahead of Quinones, he said.
“I don’t know who the heck this guy is, or what his motive was,” Quinones told the Times. “But he intentionally did not go left into a parking lot. He drove his truck directly and intentionally into our group, and you could hear him accelerate until he hit that telephone pole.”
Quinones said he saw bikes and bodies flying.
After the driver hit a telephone pole, cyclists ran up to the truck and started pounding on the windows, screaming at the driver to get out, he told the Times.
But rather than stop, the driver backed out, drove down the road, made a U-turn and then headed back towards the cyclists, Quinones said.
Payne said the driver did not comply when officers tried to arrest him, but the circumstances of the shooting were not immediately released.