The army said it has issued several warnings demanding Premium Times to retract the alleged malicious stories against the military, but the paper refused.
The army accused the media platform of publishing series of fabricated stories against the army and the Chief of Army Staff, Lieutenant General Tukur Buratai.
The Director, Army Public Relations, Brigadier-General Sani Usman, disclosed in a statement that the army decided to go to court because the online publication refused to retract the stories after being warned to do so several times.
He said the army also wrote a letter dated December 22, 2016, to the publication, demanding a retraction of the stories but no action was taken by the publication.
The letter, signed by Major General IM Alkali, accused Premium Times of publishing false stories over the insurgency in the north-east without verification from the army.
The publication was asked to retract the stories and publish same before December 31, 2016.
Instead, Premium Times demanded an apology from the army over its threat against the staff of the medium.
To this end, the army went ahead to file a lawsuit against the publication.
Usman said: "The Nigerian Army has instituted a legal action against an online publication, the Premium Times, over its failure to retract and apologies over false, subversive and malicious publications against the person of the Chief of Army Staff, Lieutenant General Tukur Buratai and the Nigerian Army. All efforts to make the medium make amend proved abortive. The medium however remained adamant and recalcitrant. Consequently, the Nigerian Army has briefed it's lawyers to institute legal action against the medium."
However, on Tuesday, January 10, Premium Times, through its lawyers, replied the Army's December 22 letter.
The publication stood by the stories in question and unequivocally rejected the demand for retractions and apology.
The news outlet gave the army a seven-day ultimatum to withdraw the allegations and threats against it and its staff, or expect a lawsuit as well.
"By your letter you have threatened the lives of our clients, and our clients are thus obliged to put the public on notice that should any harm come to them, you, the Chief of Army Staff and the Nigerian Army should be held accountable," principal counsel to Premium Times, Ogunye, wrote.
He further said: "It is our view that all working journalists and news outlets are entitled to some protection from public officers, especially of the military and security agencies who are charged with the duty to secure and protect Nigeria and Nigerians, their lives and property, and maintain law and order, but who often, because of the uniqueness of that duty and for reason of the exclusive bearing of arms and control of our commonly owned ordinance, assume very erroneously that they are above the law."
He slammed the army for questioning the professionalism of the paper and its stories, saying the military is not in a position to do that.
"The penchant of public officers to flippantly, arrogantly and ignorantly label media reports and stories and journalists 'unprofessional' once they are affected by media reports and stories must be deprecated with decorous pungency. Sir, you are not in any position at all to teach our client media professionalism, ethics and standards.
"It really can be exasperating and disconcerting to see public officers condescendingly castigate journalists, many of whom are not only internationally acclaimed and celebrated but who also have up to forty years of practice as journalists under their belt," the letter stated.
It added: "Sir, the Nigerian Army of which you spoke so glowingly is an heir to a military that unpatriotically subverted, many times, constitutional governance in Nigeria, plunged Nigeria into a three-year internecine civil war, committed unspeakable rights violations against the Nigerian people and thwarted the efforts of Nigerians to restore democratic governance to Nigeria.
"Even under the current civil government, the officers and men of the Nigerian Army continue to carry out acts that threaten the survival of democratic governance.
"The roles played by officers and men of the Nigerian Army in the Ekiti State Governorship Election in 2014; the insertion of the Nigerian Army in the partisan allegation that the WASC School Certificate of our President, Muhammadu Buhari; the seizure and confiscation of newspapers nationwide during the Presidency of Goodluck Jonathan by men and officers of the Nigerian Army under the guise of looking for terrorist elements; and the recent killings that attended the insistence on right of way by the Nigerian Army against the adherents of the Shiite Islamic Sect in Zaria, in which hundreds of civilians lost their lives, are cases in point."
It is believed that the latest exclusive report by the paper, published on Thursday, January 12, may have further pushed the army to make the legal move.
The report said, on the order of the Federal Government, the Nigerian Army is mobilising troops from various battalions across the country for a mission in Gambia - to forcefully remove President Yahya Jammeh from office - if he refuses to honorable step down by the end of his tenure this month.
But the army, in a statement issued on Thursday, strongly denied planning any attack on The Gambia or its President.