Auckland police believe two of three armed robberies in Auckland within 48 hours are linked.
Police were were called to a bar on Great North Road in Point Chevalier just before 1am on Friday.
A group armed with hammers and a firearm entered the bar where there were a number of staff and customers inside.
Detective Senior Sergeant Ash Matthews said a shot was fired which hit a TV on a wall behind the bar and money was taken from the tills and gaming machines.
"It's incredibly lucky no-one was physically injured during this incident."
Matthews said police believed the same group was responsible for an aggravated robbery at a commercial property in New North Road, Mt Albert on Wednesday night.
Four masked people armed with weapons, including a firearm, entered the building and money was taken from the cash register.
"A staff member inside the premises was uninjured but understandably shaken by the incident," Matthews said.
"We believe these two incidents are linked and are following positive lines of enquiry."
Police are also investigating a separate aggravated robbery at a commercial premises in Mount Albert about 2.20am on Friday.
A staff member and four customers were inside when up to seven people armed with hammers entered the building on New North Road.
Two of the group threatened the victims inside the store while others took a number of items before fleeing, Matthews said.
Police recovered a stolen car a short distance away on Holbrook Street, Blockhouse Bay, which is will undergo a forensic examination.
"The victims have been left shaken by the incident, but otherwise uninjured," he said.
He urged anyone who saw any of the incidents to speak to police.
"While we want to remind people never to put themselves in harm's way, we always encourage witnesses to come forward."