A section of Ferry Road in Christchurch is blocked following a crash involving a car and a pedestrian early Tuesday morning.

Emergency services were called to Ferry Road in Woolston about 5.30am.

Police said the road was blocked between Charlesworth Street and Waterman Place.

A St John spokesperson said two people were taken to Christchurch Hospital, one in a critical condition and another with moderate injuries.

The Serious Crash Unit has been advised.

Motorists are being asked to avoid the area while emergency services remain at the scene.