One person is in a critical condition and others are injured after a car hit several pedestrians in Christchurch.

A police spokesman said they are responding to a crash at the intersection of Fitzgerald Ave and Gloucester St which happened shortly before 9am.

A St John ambulance spokesman said one female patient was transported to Christchurch Hospital with critical injuries. Two other patients, who had minor and moderate injuries, were assessed and treated at the scene.

Jacob Withers said he was working nearby at McGirr Motors when he heard a car engine revving, then a loud bang.

The crash scene.
The crash scene.

"I went outside and saw one person laying on the ground, a person sitting on the ground and people running everywhere," he said.

"The people in the car were screaming and panicking. Then the fire brigade, ambulance and police all turned up on the scene.

"I was just concerned for the people involved."

Roads around the location of the crash are expected to remain closed for some time while the Serious Crash Unit works at the scene.

Fitzgerald Ave is closed from Hereford St to Avonside Dr/Kilmore St.

Motorists in the area are asked to follow the directions of emergency personnel.