Six people were taken to hospital in critical condition after Saturday’s crash in the mountainous town of Show Low, a three-hour drive northeast of Phoenix, police said.
The suspect, a 35-year-old man, was also hospitalized after being shot by police and is in critical but stable condition.
Crumpled helmets, shoes and bikes were strewn across the street after the crash, a tire stuck in the truck’s grille, which had damage to the top and sides and a bullet hole in a window.
Two other people went to the hospital themselves, city spokeswoman Grace Payne said. One of the seriously injured was then transported 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 van struck cyclists at around 7:25 a.m. (2:25 p.m. GMT) during the annual 93 km (58 mile) Bike the Bluff race before fleeing.
Police prosecuted the driver and attempted to arrest 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 riders aged 55 and over when a black van was driving in the opposite direction crossed three lanes and headed towards the cyclists.
He assumed the driver was turning in a parking lot. Instead, the driver drove straight into the cyclists ahead of Quinones, he said.
“I don’t know who the hell this guy is, or what his motive was,” Quinones told The Times. “But he didn’t intentionally go left into a parking lot. He drove his truck directly and intentionally into our group, and you could hear him speeding up until he hit that telephone pole.
Quinones said he saw bikes and bodies stolen.
After the driver hit a telephone pole, the cyclists ran towards the truck and started banging the windows, yelling for the driver to get out, he told The Times.
But rather than stop, the driver backed up, rolled down the road, turned around and then walked towards the cyclists, Quinones said.
Payne said the driver did not comply when police tried to stop him, but the circumstances of the shooting were not immediately disclosed.