One reporter, named as Marciano Candia, is thrown to the ground after an army member appears to grab him by the neck, the video – which has been broadcast on national news – shows.
The soldier then turns to wrestle another person in casual clothes, before taking a swipe at the camera.
Mr Candia and other journalists were on a military site to cover an alleged eviction, according to Paraguay’s Union for Journalists (SPP).
Other soldiers stand nearby, holding onto their guns and watching while Mr Candia is tackled to the floor.
Paraguay’s armed forces said in a statement that an argument and altercation took place between a soldier and a journalist after a group of people who had entered state property were asked to leave.
They said police on the ground arrested three trespassing citizens.
The army have asked the attorney general’s office and the Public Prosecution Office to look into the incident.