A man has been arrested in the Christchurch suburb of St Albans following an imitation firearms incident.

A police spokeswoman said they received a report just before 5pm that a person had been seen waving what looked like a firearm at passing motorists on Edward Avenue.

An eyewitness said at least 12 police cars were on Edward Street.

The police spokeswoman said police have taken the man into custody and have located an imitation firearm.

She said no details were available on what charges the man will face.