A 26-year old man has been charged with kidnapping and firearm offences after allegedly abducting a man from an outback pub in the Northern Territory and forcing him to drive almost 300 kilometres.

Police have released footage of the arrest, which happened at the back of Katherine's public library just after midnight on Wednesday morning.

In the footage, a shirtless man wearing dark shorts can be seen throwing a long-barrelled gun to the ground and then doing the same with a pistol, before laying face-down with his arms outstretched.

An NT police officer moves in to arrest the man moments before several other officers arrive in an unmarked white ute.

The man allegedly entered the pub in Daly Waters at about 9pm and threatened patrons with the weapons.

A male patron at the pub was then "accosted", according to police, and forced to drive the alleged offender to Katherine.

Weapon fired, police say

The suspect allegedly fired one of the weapons inside the car on the way but no-one was injured, police said.

The man has been charged with 11 offences, including recklessly endangering life, possessing guns without a licence, altering a gun, kidnapping and depriving a person of liberty.

NT Education Minister and Member for Katherine Jo Hersey said her thoughts were with the alleged victim.

"I think it's just great that the police did such a great job using the CCTV cameras and apprehending that man," she told the ABC.

The alleged offender is being held in police custody and will face court in Darwin on Monday.

Police are urging members of the public who may have witnessed the incident to come forward.