"A car loaded with explosives ... exploded before reaching the Naranjitos military base. As a result, two occupants of the vehicle were killed and four soldiers were injured ... They are in stable condition," Rodriguez said in a video posted by the Arauca government on Twitter.
Rodriguez added there was no information about the organizers of the attack.
Unconfirmed cellphone footage documented the immediate area and the response by emergency personnel has since surfaced on social media.
Colombian President Gustavo Petro tweeted he instructed the country's ministry of defense to investigate the incident, adding that the government will not tolerate intimidation of the population.