A terrified service station worker had a high-powered rifle pointed at them over the counter when two robbers burst into the Masterton store on Wednesday night.
Detective Senior Sergeant Barry Bysouth said two people entered the BP petrol station on Chapel St shortly after 9pm.
They were dressed in dark clothing and had their faces covered.
The pair threatened a petrol station employee, who was working alone at the time, with a firearm and demanded cash and cigarettes, Bysouth said.
They left the BP and headed towards Renall St and then possibly west towards Pownall St junction.
Police described the offenders as being male, Māori and between 20-25.
"The firearm they presented during the robbery is a distinctive rifle and someone may recognise it," Bysouth said.
"We urge anyone in Pownall Street who has CCTV or anyone with information regarding this incident to please contact Police."
Bysouth said it was a frightening incident for the employee.
BP 2go Masterton director Akash Sood told the Herald the employee's instinct and training kicked in and he did all the right things.
"I'm his employer and I wouldn't want to be in that position. I don't know if I would have been able to cope as well as he did if I was put in that position."
He came in to do his shift the following day, despite being encouraged to take a couple of days off, Sood said.
"He has been offered victim support. The police have been really supportive and helpful and we're arranging private counselling as well."
Police are also keen to speak to the driver of a car that drove past the pair immediately after the robbery took place.
Anyone with information that may assist police with their inquiries is urged to call 105 and quote the file number 210805/2963.