A 24-year-old Belconnen man has been charged after police allegedly found a 3D-printed firearm and a large knife in his possession at the Civic bus interchange.

Police say officers on patrol in Alinga Street about 3.15pm on Monday saw the man damaging a pole at the interchange.

When officers attempted to speak with him, the man allegedly resisted arrest and tried to fight police.

A search of his belongings allegedly uncovered a 40cm curved knife, a 3D-printed firearm, firearm parts and ammunition.

He has been charged with defacing public property, resisting a Territory official, possessing a knife without reasonable excuse, unlawful possession of a prohibited firearm and possession of ammunition.