One person seriously hurt after trailer smashes into parked car on Auckland's North Shore

Police have closed the road between the corner of Beach Rd and Waiake St, and the intersection of Beach Rd and Ellangowan Rd.

A person has been seriously hurt after a trailer came loose from a vehicle and smashed into a parked car on Auckland's North Shore.

Three people were inside the parked car, and one is now seriously hurt. Two others have moderate injuries.

Police are at the scene at Beach Rd in Waiake, an area between Browns Bay and Torbay, after the accident at about 3pm.

A witness told the Herald the trailer was carrying a jetski.

"(The trailer) has come off a moving vehicle and ploughed into beach crowd at Waieke Beach," she said.

"Multiple injuries and police, ambos on scene."

The road has been closed between the corner of Beach Rd and Waiake St, and the intersection of Beach Rd and Ellangowan Rd. Motorists are asked to avoid the area.