Emergency services called to Nelson Police Station

One person is in a critical condition after what police are calling an incident near the Nelson Police Station.

People were asked to avoid the area, although police say they are not seeking any one else and there does not appear to be any threat to public safety.

A cordon was established nearby at the corner of Harley St and Hardy St, which has since been removed.

An ambulance and critical care vehicle were spotted at the scene off Bridge Street, though details of the callout are unclear.

In a statement, Hato Hone St John said it was called at 11.35 Wednesday. A helicopter, ambulance, rapid response and operations manager were sent to the scene.

"One patient is being transported to Nelson Hospital (by ambulance) in a critical condition."

St John referred further requests for comment to police.

A ute was towed from the scene though it is not known whether it was connected to the incident.