Khabib Nurmagomedov takes down Conor McGregor during their UFC 229 bout last fall. (John Locher/Associated Press)

So much for any notion that the very, very bad blood between Conor McGregor and Khabib Nurmagomedov ended with McGregor’s announced retirement. The Twitter war between the two MMA stars got uglier Wednesday, even as UFC President Dana White called the situation “unacceptable” and said he was taking “steps” to rein in the antagonists.

In response to a jab by Nurmagomedov on Tuesday, McGregor lobbed an insult at the wife of the UFC lightweight champion. After about 15 minutes, McGregor deleted the tweet and went on to call for a rematch with Nurmagomedov, who beat him via fourth-round submission in a UFC 229 lightweight title fight in October.

“Your wife is a towel, mate,” he tweeted along with a photo from Nurmagomedov’s wedding in which the bride’s head and face are covered. McGregor’s tweet about the Russian fighter, a devout Sunni Muslim, was captured by MMA Junkie before being deleted. Nurmagomedov and his wife, whose name is not publicly known, have been married since 2013, and the couple has two children.

Nurmagomedov responded by calling McGregor a “rapist,” referring to reports that the Irishman was under investigation for an alleged sexual assault in Dublin. Posting a photo Wednesday of his nemesis with a woman reported to be someone other than Dee Devlin, McGregor’s girlfriend and the mother of his two young children, Nurmagomedov added: “You are a hypocrite who is not responsible for your actions. Justice will find you. We will see.”

That had White issuing a statement in which he said he was “aware of the recent social media exchange” between Nurmagomedov and McGregor. “The ongoing situation has escalated to a level that is unacceptable,” he declared. "As such, we are taking the necessary steps to reach out to both athlete camps and this situation is being addressed by all parties internally.”

However, McGregor returned to Twitter after that and posted a comment suggesting that Nurmagomedov had married a goat. McGregor again deleted the tweet shortly thereafter, but not before getting an ominous-sounding reply from Nurmagomedov: “If you think that insulting entire religion you be safe, you are mistaken.”

Nurmagomedov’s comment earlier Tuesday seemed to set off the latest round of vitriol between the two. Nurmagomedov compared McGregor to “a jealous wife” in expressing doubt about the sincerity of McGregor’s retirement, which he announced abruptly last week on Twitter. “I don’t think he’s finished,” Nurmagomedov said in a speech in Moscow. “Conor acts like a jealous wife who says ‘I will leave’ all the time but then comes back.”

After deleting his first tweet, McGregor (21-4 MMA, 9-2 UFC) pivoted to talking rematch with Nurmagomedov (27-0, 11-0). “Don’t be scared of the rematch you little scurrying rat,” he wrote. “You will do what you are told like you always do.”

That kind of exchange between the two fighters wasn’t really surprising, no matter the status of McGregor’s retirement. Both men and their camps sparred verbally and physically with trash talk that reached a personal level during the run-up to UFC 229, when McGregor talked about Nurmagomedov’s father, his religion and his country. Nurmagomedov cited those comments in explaining why, after beating McGregor, he jumped out of the Octagon and went after McGregor’s corner, touching off a brawl that resulted in suspensions for both men.

In early March, McGregor completed the terms of a plea agreement in New York that stemmed from an incident before UFC 223 last April in which McGregor attacked a bus bearing UFC fighters and staffers at Barclays Center. The agreement, which also involved pleading guilty to a count of disorderly conduct, enabled the Irishman to avoid a possible jail sentence and deportation. McGregor, according to the New York Post, performed “menial tasks” at churches to fulfill that part of the agreement. He still faces civil lawsuits stemming from the incident and was ordered to undergo anger-management counseling as part of the plea agreement.

On March 11, he was arrested in Miami on strong-arm robbery and criminal mischief charges after he allegedly smashed and stole a fan’s cellphone outside a nightclub. “Patience in this world is a virtue I continue to work on,” he said on social media soon after that.

Last week, McGregor announced his retirement, saying on Twitter, “I wish all my old colleagues well going forward in competition.” However, more than a few in the world of MMA doubted that he was completely serious about never fighting again.

Later Wednesday, McGregor appeared to signal an end, at least for the time being, to his online battle with Nurmagomedov — and to his retirement — by tweeting, “I want to move forward, with my fans of all faiths and all backgrounds. All faiths challenge us to be our best selves.”

He added, “Now see you in the Octagon.”

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Sorry we doubted you, March Madness. Your latest was a masterpiece.