An armed man has been tasered and arrested for allegedly driving erratically through Melbourne's CBD, with the Bomb Response Unit now on scene.
Police say they were called to the corner of Swanston and Flinders Streets shortly before 8am on Saturday morning.
It's believed bystanders attempted to help stop the car by throwing a bike underneath it.
The Critical Incident Response team then subdued the man, believed to be in his twenties, who is now assisting detectives with their enquiries.
No one was injured during the incident.
Officers from the bomb squad were called in to comb through his car as a precaution.