Possible terror link in Queanbeyan service station worker stabbing

Counter-terrorism police are investigating the fatal stabbing of a Queanbeyan service station worker after the letters IS were written on the store's window in blood.

A service station worker, Zeeshan Akbar, 29, suffered several stab wounds in an altercation at about 11.45pm on Thursday, before he was found by another employee when they arrived at work overnight.

The workmate gave first aid, but the victim died at the scene soon after.

The two teenage boys, aged 15 and 16, were arrested over the incident on Friday, after a cross-border police chase.

Photos taken at the service station crime scene show a window covered with paper, concealing the message scrawled in blood.

Mr Akbar was just minutes from the end of his shift at the Queenbeyan Caltex when police allege the two teens attacked, following a crime rampage.

Locked inside the service station police suspect the pair grabbed the cash register and smashed their way out.

Police say they then continued on a crime spree which began hours earlier at a bottle shop in the same NSW town.

It's alleged the pair also bashed a man with a beer bottle in a Queanbeyan park and that at about 9.30pm they attacking another man with a tyre iron during a break and enter.

Following the fatal service station stabbing, they're alleged to have knifed a man on Stornaway Road.

A witness gave police details of a silver Ford Falcon.

It was spotted nearby and after a short pursuit the two teenagers were arrested on the Monaro Highway.

NSW Police Force Deputy Commissioner Catherine Burn said investigators will examine the motivation behind the attack and other criminal incidents that occurred in Queanbeyan and the ACT overnight which "may be related to terrorism".

“We have two teenagers in custody and sufficient information to believe the actions of one of those teenagers may be related to terrorism," she said.

"That information comes from physical evidence at the scene and other sources."

"We are also looking at number of other incidents involving an attempted robbery at a bottle shop in the ACT, an attack on a homeless man in Queanbeyan, an assault at a unit in Queanbeyan and later an attack where a man was stabbed and his vehicle stolen," Ms Burn said.

The crime spree and subsequent police chase went across state borders and the boys were arrested in the ACT.

The teens are being held in an ACT watch-house with NSW Police requesting their extradition.

Police said both the boys were known to police and they are focused on the older boy's possible extremist links.

But investigators also searched the younger boy's home today and his family said they were astounded by the allegations against him.

Officers are also investigating whether drugs may have played a part in the senseless violence which left three injured and cut Mr Akbar's life short.

There was a significant amount of damage done to the service station, police alleged.

Anyone with information is encouraged to call Crime Stoppers 1800 333 000 or use the Crime Stoppers online reporting page.