An argument over corn chips escalated to the point where one man allegedly threatened another with an axe, Northern Territory police say.

Duty Superintendent Louise Jorgensen said police were called to a disturbance near the Darwin Post Office around 2:00pm on Sunday.

"Two males began arguing about a packet of Doritos. Apparently one was not sharing," Superintendent Jorgensen said.

"The argument escalated and some Transit Safety Officers nearby attended and attempted to break things up."

Superintendent Jorgensen said one of the men picked up a stick and threatened the other.

"The other male then casually got up, strolled over to a witch's hat, lifted it up and grabbed an axe which had been hidden underneath," she said.

"He then walked straight towards the other male threatening to hit him."

She said Transit Safety Officers then asked the man to drop the weapon.

"When he refused they approached and tackled him to the ground. They held him until police arrived and executed the arrest," she said.

Superintendent Jorgensen said the man was charged with threatening behaviour and going armed in public.

She thanked the Transit Safety Officers for their actions.

"There were a number of members of the public around at the time and credit must go to the officers whose actions undoubtedly prevented escalation of the incident and injury to persons in and around the scene," she said.