Emergency services are at the scene of a crash involving two vehicles in Woolston.
A police spokesman told chrislynchmedia.com the crash on Ferry Road was reported at 3.30pm.
A St John spokeswoman said they sent an ambulance and a rapid response unit.
One person has been transported to Christchurch hospital in a serious condition.
The eastbound lane is currently closed while emergency services attend the scene.
A witness said traffic was earlier being diverted to Smith St (coming from the city.)
Ferry Road was partially blocked at Te Waka Unua School.
Motorists are being asked to avoid the area and expect delays, the police spokesman said.