PHOENIX -- A group of men with baseball bats and a steel rod attacked a man on a bicycle Monday, then hit him with a car, witnesses said.

The attack happened shortly before 4 p.m. near Encanto Park in Phoenix.

A witness, who asked to be identified only as Stephen, said the victim was riding his bicycle north on 15th Avenue when the attackers climbed out of a car and went after him.

"They were yelling at him. One guy had a bat, another one had a steel -- looked like a rod," Stephen said. "When I see somebody running with a bat, chasing somebody, you know something's going to happen."

Stephen said the men assaulted the victim with their weapons, then stood back as the driver of a second car accelerated and crossed the center line to hit the victim.

"When that vehicle hit that guy on the bike, I swear to God, he flew 10 feet up and he looked like a rag doll," Stephen said.

Another witness gave the victim CPR until paramedics arrived to take him to the hospital. Police said the man was in extremely critical condition Monday night.

Witnesses gave police the license plate numbers of the two cars, and police said they took four men into custody.

Police did not identify the men and said they were investigating a motive for the attack.

"Using a vehicle as a deadly weapon is pretty rare," one officer said.