Brendan Cannard and Brandon Stephen Kennedy-Jones, both 19, appeared in Muswellbrook Local Court in handcuffs on Monday charged with a string of arson, robbery, break and enter and weapon offences.

The pair were both refused bail and will next appear in Singleton Local Court in April. Rural crime investigators say they established Strike Force Carribee in October to investigate a number of alleged arson and property offences around the Singleton area.

Police say the incidents include two computer terminals being damaged by rocks in Glennies Creek on September 2 before a structure on Middle Falbrook Road, two hay bales and two residential garbage bins were set on fire. A few weeks later three firearms were stolen from a remote property at Putty Road, Milbrodale.

On Christmas Day a tractor was located burnt out in a paddock on Tilpa-Tonga Road, Tilpa, about 800 kilometres west of Singleton.

Then on January 19 this year, machinery and other equipment were stolen from a work site on Goorangoola Road, Goorangoola.

An excavator and diesel petrol were also stolen from the same site ten days later.

Earlier this month, two firearms were stolen from a rural property on Old Carrowbrook Road, Mount Olive. And then just before midnight last Wednesday two armed men entered a service station on Bridgman Road, Dunolly, and allegedly threatened a female employee. The woman handed over a sum of cash before both men ran from the scene.

Following extensive inquiries, strike force detectives went to a business at Muswellbrook on Sunday and arrested a 19-year-old man. Police also seized a white Toyota HiLux for further examination.

The other 19-year-old was arrested at Singleton police station a short time later.

Police then searched properties at Bridgman and Muswellbrook where a machete and other items were allegedly seized. Following further inquiries, officers attended an area of bushland in Bridgman where they located and seized five firearms hidden in PVC piping.