Police are investigating three robberies at Auckland service stations within kilometres of each other inside a week.
The latest station hit was a Caltex on Great South Rd about 1.30am yesterday. The thieves left the scene in a brown minivan.
The service station was cordoned off and police were carrying out a scene examination.
A police spokeswoman said the circumstances were similar to an aggravated robbery at a Mobil on the Mt Wellington Highway a day before where a shot was fired.
Police were working to establish whether the two robberies - about 3.5km apart - were connected.
Two people, one armed with a shotgun, arrived at the Mobil petrol station about 1.25am and demanded to be let inside.
The two people working at the petrol station retreated to a locked back office, police said.
The offenders got in after smashing a glass panel in a door then fired a shot in an attempt to get access to the counter area.
They took the till drawer and tobacco products, police said.
CCTV footage revealed the face of one of the offenders when his mask slipped below his nose.
They left in a white Nissan.
The first service station hit was on Good Friday in Apirana Ave in Glen Innes, about 4.9km from Wednesday's robbery.
