He's told his forces to shoot Russian officers operating in his fiefdom without his permission, accused the U.S. government of complicity in the 2013 Boston Marathon bombing, and blessed the reportedly bigamous marriage of a local police chief to a minor.

Such have been the recent exploits of Ramzan Kadyrov, the Kremlin-backed leader of Russia's Chechnya region whose pronouncements and behavior have appeared increasingly mercurial, even for a man already renowned for his flamboyant -- and often menacing -- public persona.

They come amid heightened tensions between Kadyrov and federal Russian officials since the slaying of Russian opposition politician Boris Nemtsov near the Kremlin on February 27.

Kadyrov has publicly defended a main suspect in the crime, which Russian President Vladimir Putin has called "shameful." And even as the Kremlin has awarded Kadyrov with various state honors, he and his top officials have in recent months displayed defiance toward dictates from Moscow on issues ranging from polygamy to security.

Last week, Kadyrov went on the offensive against users of the Facebook-owned application WhatsApp, upbraiding local women he accused of using the online messaging service to rumormonger about the nuptials between Chechen police chief Nazhud Guchigov, reportedly already married and in his 40s or 50s, and a 17-year-old girl.

Addressing the women's husbands at a May 18 meeting broadcast on local television, Kadyrov told the men that their wives "won't write these things" if they "keep them at home" and "don't let them out."

"They're on WhatsApp all night long. Make them work. Let them work in the garden. Let them work in the greenhouse," he told the alleged offenders of local mores as they stood around him in a circle looking gloomy and deflated.

'Shoot To Kill'

Putin has essentially handed the keys to Kadyrov to run Chechnya as he sees fit in exchange for ensuring stability in the mainly Muslim republic, the site of Moscow's two brutal wars with separatists and Islamic militants over the past two decades.

A former rebel fighter turned Kremlin loyalist, Kadyrov assumed the region's presidency in 2007 at the age of 30 and has largely stamped out an Islamic insurgency in Chechnya that has migrated to neighboring Russian regions in the North Caucasus.

Critics, meanwhile, accuse him of deploying his battle-hardened local security forces to commit human rights abuses against civilians and extrajudicial killings of opponents in Chechnya, other Russian regions, and abroad.

At the same time, Kadyrov has portrayed himself as a beacon of Islamic piety and Chechen cultural traditions, even those at odds with federal Russian laws.

His backing of the marriage between Guchigov and the 17-year-old schoolgirl, who according to a Novaya Gazeta report was initially opposed to the union, has sparked a national debate in Russia about polygamy, which is banned in the country but which Islamic law permits.

The bride's age has also raised eyebrows, with critics noting that Russia's legal marriage age is 18, and others noting that the country's Family Code allows regions -- including Chechnya -- to set a lower legal age.

Guchigov was already married when the story of his planned wedding to the teenager emerged, according to some media reports. Other reports said his marriage to his first wife had not been formally registered.

Following the May 16 wedding, which the bride later said she consented to, Kadyrov's chief of staff said Russia should legalize polygamy.

Kadyrov has also issued threats against federal Russian law enforcers.

At an April 21 meeting in Chechnya's capital, Grozny, Kadyrov told Chechen law-enforcement officials that "if any [security officer], whether from Moscow or Stavropol, appears on your territory without your knowledge, shoot to kill. They have to take us into account."

The outburst was triggered by an incident two days earlier in which a Chechen man was killed in a joint operation by police from the neighboring Stavropol region and a Russian Interior Ministry Unit.

The Interior Ministry called the remark "unacceptable," and Kadyrov later walked his comments back, saying he had made them "based on emotions."

Instagram Strongman

Kadyrov's most visible public platform is Instagram, another Facebook-owned social-media platform for which he appears to harbor less venom than for WhatsApp.

Having recently crossed the 1-million-followers mark on his Instagram page, Kadyrov regularly posts a mishmash of political musings, photo ops, and short videos highlighting his passion for sports.

Some of his most politically charged public statements in recent months have been disseminated via Instagram.

After a Boston jury last week handed a death sentence to convicted bomber 21-year-old Dhokhar Tsarnaev, whose father is Chechen, Kadyrov said he does not believe the attack could have been carried out "without the knowledge of U.S. security services."

He also used Instagram to defend the marriage of the Chechen teen to the police chief by quoting Russia's national poet Aleksandr Pushkin and denouncing a prize-winning journalist for the independent newspaper Novaya Gazeta for reporting that the girl was being forced into the union against her will.

The journalist, Yelena Milashina, came to Chechnya to spread "liberast lies paid for from abroad," he wrote, using a derogatory term likening liberals to "pederasts."

Kadyrov, of course, was known for colorful antics long before his recent turn on the center stage of Russian political life, including snuggling with a tiger and posing with a wolf.

But political commentators say his actions since Nemtsov's assassination represent a fundamental shift in his public conduct toward Moscow.

"He's pushing things further because he believes he can push things further," erstwhile Kremlin insider Stanislav Belkovsky, head of a Moscow-based think tank, told Ekho Moskvy radio in a May 20 interview.

Aleksei Venediktov, Ekho Moskvy's well-connected editor in chief, said in an interview with Znak.com this week that tensions between Kadyrov and powerful security officials in Moscow had long been bubbling beneath the surface.

"The conflict spilled into the public after Nemtsov's murder, but objectively it was always there," Venediktov said.

Venediktov noted that he has taken additional security measures after what he believes was a threat Kadyrov made against him in a January 9 Instagram post in which he accused the journalist of promoting "anti-Islamic" sentiment.

"That was before Nemtsov's murder, and I hired additional security personnel at that time," Venediktov said.

With reporting by Reuters, echo.msk.ru, and znak.com