The head of Russia's National Guard has challenged Aleksei Navalny to pick up a sword and duel it out with him in classic 19th-century fashion, after the opposition politician accused the organization of billions of rubles in corruption.

In a seven-minute YouTube clip in which he appears in full dress uniform, cap, and epaulets, Rosgvardia Director Viktor Zolotov vows to "make mincemeat" of Navalny, who is currently behind bars serving the latest of his sentences for his political activities.

"I simply challenge you to a duel, in the ring, on the judo mat, anywhere, and I promise to make mincemeat of you," Zolotov, a former steelworker and longtime security chief for President Vladimir Putin, says after accusing Navalny of "offensive, slanderous remarks."

In its latest corruption probe, Navalny's Anticorruption Foundation last month alleged that at least $29 million in procurement contracts had been stolen from the National Guard.

In his September 11 response, Zolotov laments the demise of the dueling tradition and clenches his fist at the camera, saying he is "seeking satisfaction" before challenging Navalny to the duel.

Zolotov, who also sits on the Russian Security Council, acknowledges the National Guard has some "corruption shortcomings" but says they are being tackled.

Asked about Zolotov's video, Kremlin spokesman Dmitry Peskov said he "can well understand" his motivations.

"You know, sometimes any possible methods should be employed in opposing shameless libel," Peskov said in comments quoted by Interfax. "When there is really shameless libel, which is nothing but a violation of the law, surely, such libel had better be nipped in the bud."

Peskov added that Putin had not "previously cleared" Zolotov's statements, adding he didn't think it constituted a genuine threat.

Others were more critical of Zolotov's challenge.

Taking to Twitter, blogger and Putin critic Rustem Adagamov said it was far from chivalrous to challenge a man behind bars to a duel. "To call a man who is whiling away his time behind bars to a duel, and speak at the same time about officer honor? A real guardsman. No comment."

In its investigation, published on August 23, Navalny's group accused the National Guard of skimming money from the budget for fruit and vegetables.

Political Prisoners

Navalny has repeatedly been jailed for organizing protest rallies.

But his arrest outside his home on August 25 came as a surprise, since police were detaining him over a demonstration held in January. A Moscow court sentenced him two days later to a month in prison for an unsanctioned protest.

Navalny had called for nationwide rallies on September 9 to protest the Russian government's plans to raise the retirement age for both men and women.

The pension issue has created widespread anger, uniting Russians with widely varying political views against the proposal and denting Putin's popularity.

More than 1,000 Russians were detained across the country during the protests, which coincided with local and regional elections.

Footage of the rallies showed police forcibly dispersing the gatherings, hitting demonstrators with batons and dragging them away. Images of police officers detaining young children quickly went viral.

Amnesty International said Russian police had "stooped to a new low" by detaining "dozens of teenagers."

Fourteen journalists were among those detained, and three more were victims of violence, according to the independent Trade Union of Journalists and Media Workers.