A knife-wielding man wearing a balaclava tried to steal cigarettes and cash from a Nelson service station early this morning.

But the would-be robber was thwarted when a staff member activated a panic alarm.

Detective Sergeant Ian Langridge said the man entered the Mobil service station in Tahunanui about 3am armed with a small knife.

He demanded the staff member open the cigarette cabinet and till.


"The staff member has done the right thing by activating a panic alarm, and the man left without taking any property," Langridge said.

The man was last seen walking north along Tahunanui Dr. It was possible he had a bike or car waiting nearby.

Police are now asking for any sightings of the man pictured. He is described as 1.76m tall, of thin to medium build, and wearing a balaclava.

Langridge said police were advising business owners to review their late night security arrangements.

"This type of offending is a concern and has the potential to result in someone being injured," he said.

"Employees should be aware of the risks of working alone, and employers need to discuss with their staff the appropriate response when confronted by an armed or angry offender."

Anyone with information, or who was in the Tahunanui area at the time, is asked to call Nelson Police on 03 546 3840 or Crimestoppers, anonymously, on 0800 555 111.