Two 15-year-olds and a 13-year-old have been arrested over a burglary in Whangārei and an aggravated robbery in Ruakākā.

The burglary was at the Spark store on Cameron St in Whangārei around 7pm on Monday.

The offenders smashed glass to gain entry, police said, then stole some stock and fled in a vehicle.

The same teenagers then allegedly entered a petrol station in Ruakākā, where they threatened the attendant just before 7.30pm.

Cash and cigarettes were stolen and the teens continued to drive south.

Police said they did not pursue their vehicle, but continued to monitor it. It was signalled to stop near Kaukapakapa.

The occupants abandoned the vehicle and fled on foot into a nearby property.

The three teenagers will appear in the Waitākere Youth Court.