The 29-year-old service station attendant was stabbed multiple times inside the Caltex service station on Bungendore Road in Queanbeyan, near the NSW-ACT border, just before midnight on Thursday.

The man's colleague arrived at the service station to start his midnight shift only to find his injured colleague lying on the floor, and the service station's front windows smashed. The man could not be revived, and died at the scene.

Police allege two boys, aged 15 and 16, stabbed the service station attendant during a violent and "horrific" rampage in the Queanbeyan area. The boys also are accused of bashing another man with a tyre iron during a home invasion, bashing another man in a park with a beer bottle, before stabbing another man in the stomach about 6.20am on Friday on Stornaway Road in Queanbeyan.

That stabbing victim has been taken to Canberra Hospital in a serious but stable condition, Superintendent Rod Smith said.

A witness to the latest stabbing on Friday morning told police the offenders escaped in a silver Ford Falcon. Soon after, police began chasing the vehicle, which crossed across the border from Queanbeyan into the ACT.

"That pursuit finished shortly after with both of those offenders being arrested without incident," Superintendent Smith said.

"They're currently being taken to the watchhouse in the ACT, and we're in the process of issuing warrants, and we will be seeking their extradition back to NSW where obviously our investigations will continue into these matters."

He described the night's events as "horrific".

"It doesn't need to be said, but it doesn't get more serious than this," Superintendent Smith said.

"It's an absolutely horrific series of events, and we'd just like to reassure everybody that there are two people that we believe are involved, and both of those people are currently in custody."

Officers from Monaro Local Area Command have established a crime scene at the service station, which was damaged in the attack and is being forensically examined.

Superintendent Smith said the service station's front doors had been locked during the stabbing, trapping the two alleged offenders inside. The alleged offenders had to "smash their way out" the front windows to escape, he said.

He said police were not aware of any relationship between the boys and the victims.

Police are also investigating whether the boys have any link to another attempted robbery overnight in the ACT.

Queanbeyan residents quickly took to social media to share their distress at the tragic news.

"I used to go here all the time, the staff we all really wonderful," a local said.

"They are genuine and ask how your day is going. My thoughts are with them and their family."

Another added: "This is so incredibly sad. They are the nicest people who work there and that is heartbreaking for all of them and the poor family who don't have their loved one."