A man has been arrested after a motorcyclist was seriously injured in an alleged stabbing in Christchurch on Thursday afternoon.

Emergency services were called to Opawa Road, near Garlands Road, at 4.45pm.

A woman who was among the first on the scene described the frantic moments after the attack as she worked to give first aid.

She told chrislynchmedia.com she was alerted by someone rushing into her workplace asking for help after a man had been stabbed nearby.

After making sure those around her were safe, she ran outside to assist.

“The motorcyclist was on the side of the road, in a lot of pain, and asked me to call his partner, which I did, and calmly explained what had happened,” she said.

She said other witnesses saw the motorcyclist pull over near a bus stop when the occupant of a following vehicle stopped, got out, and stabbed him.

The woman believed the attack may have been linked to a road rage incident but said that was still unclear.

She said another woman nearby took off her cardigan to help apply pressure to the wound before she took over.

“I was applying a lot of pressure to the left side of his stomach to stop the bleeding,” she said.

She praised the quick actions of those who assisted during what she described as a distressing situation.

The offender fled before officers arrived.

The motorcyclist was rushed to Christchurch Hospital by ambulance, where he underwent emergency surgery.

A police spokeswoman said a 29-year-old man is due to appear in Christchurch District Court on 12 March charged with wounding with intent.

Police officers were still at the scene hours after the incident.