Armed police are on the streets of a city suburb this afternoon after a second serious incident in West Auckland today.

Police would only confirm they are "attending an incident in Kelston" with updates to follow "in due course".

But a witness told the Herald they had seen armed police stop a vehicle on Barbary Ave, with its three occupants detained and police officers searching the vehicle.

The witness also saw two armed police officers with road spikes - not laid, but ready to be - at another Kelston street, while two more armed officers were parked in the driveway of a home on Daphne St.

There is also police activity in the St Leonards Rd, Laura St and Kelman Rd areas.

Police dogs have also been seen in the area and the Eagle police helicopter is circling above.

The drama began about 1.20pm.

Earlier today a man suffered serious gunshot wounds in West Auckland, with police mounting an operation in the area.

The injured man was treated by paramedics near a BP station in Te Atatu South, while police also separately locked down a street in New Lynn.

Police believed the man drove to the Te Atatu South petrol station after being shot at a home on Hutchison Ave in New Lynn this morning, a police officer said.

However, police said at the time no manhunt was underway and no other sites were connected with the shooting.