Two buses have collided in Central Wellington.

Police say the collision happened on the corner of Willis Street and Lambton Quay just after 11am.

Newstalk ZB Reporter Frances Cook was on the bus.

She says the drama started when one bus tried to overtake another at a busy intersection. Horns blared, but it didn't stop the nasty side-on smash, which sent passengers sprawling on the floor.

One woman suffered a blow to the head which left her dazed and confused.

Ambulances were called to the scene to take care of passengers, resulting in traffic chaos in the city centre.