A woman has been arrested after colliding with three motorcycles, seriously injuring one rider, while driving under the influence of alcohol this afternoon.
A police spokesperson said officers were alerted to the crash at the intersection of State Highway 1 and Whitaker Rd at 3.50pm.
The woman driving the car failed to stop following the accident in which she ran over one female motorcyclist.
"A driver, impaired by alcohol, collided with a total of three bikes in Warkworth. One of them stayed upright and the other two were knocked down, causing their riders to be injured," a police spokesperson said.
A motorcyclist in her 20s was airlifted to Auckland City Hospital in a serious condition by Westpac Rescue Auckland following the accident.
"Crew believe she was hit from behind and run over suffering multiple injuries," a Westpac Rescue Auckland spokesperson said.
Police, fire and ambulance attended the scene of the accident.
"One person has serious injuries and another has moderate injuries," a police spokesperson said.
"The car involved left the scene and was located a short distance away.
"One person is assisting police with inquiries.
"The road is closed and motorists are asked to avoid the area."