A car is submerged in water after running off Main Road in the Christchurch suburb of Clifton.

The car went off the road between Mulgans Track and Clifton Terrace.

Police say they don't yet know how many people were in the car, however we have also had unofficial word that one person is trapped in the car.

A local resident says there is a full emergency response, with ambulance and police at the scene, and a chopper in the air and lifeboat out on the water.

The resident says the tide is out, but it's now growing dark.

The road into Sumner is closed, but there is a detour via the Summit Rd.