MOSCOW (Reuters) - A commando raid to detain the man who ran Russia’s most violent big city is one of the boldest gambles in years by President Vladimir Putin to assert control over Dagestan, a region spiraling into organized crime and Islamist insurgency.

Russian President Vladimir Putin meets with businessmen and entrepreneurs at Voronezhsintezkauchuk plant, producing synthetic rubber and latex, in the city of Vorovezh, May 23, 2013. REUTERS/Mikhail Klimentyev/RIA Novosti/Pool

The mayor of Dagestan’s capital Makhachkala for 15 years, Said Amirov was so powerful - and the Kremlin so determined to show its own muscle - that special forces from Moscow were sent to arrest him with helicopters and armoured personnel carriers.

Dagestan, in the spotlight as the place where Boston Marathon bombing suspect Tamerlan Tsarnaev spent the first half of 2012, is the main focus of an insurgency by fighters who want to found an Islamic state in Russia’s Caucasus mountains.

By taking down one of his own most feared local strongmen, Putin has made clear that the Kremlin still calls the shots. But he also risks creating a power vacuum, which could prod militants to go on the offensive and gangsters to go to war over turf, less than a year before Russia hosts the winter Olympics on the other side of the mountains.

The big fear in the mainly Muslim region is that a mafia-style battle will now erupt over the business and political interests Amirov controlled.

“This came as a shock to everyone,” Alexei Malashenko, an expert at the Moscow Carnegie Centre think tank.

“To risk this on the eve of the Olympics is dangerous,” he said. “The Kremlin was tired of dealing with a loyal but unmanageable mayor. He did whatever he wanted ... he ruled a state within a state, and it could not continue any longer.”

Russian investigators say Amirov is suspected of murder. His lawyer, Mark Kruter, said Amirov had committed no crime and that his arrest was political revenge by rivals.

Rather than trust local authorities to hold the mighty mayor, federal police airlifted him to a secure Moscow jail.

Until Saturday, Amirov had seemed untouchable, protected by the Kremlin as the local boss of Putin’s United Russia party.

Even the region’s other most powerful man, Dagestan’s newly-appointed Kremlin-backed provincial chief, was not informed in advance, finding out the arrest was under way while he was watching a football match: “It was an initiative of the Russian president to carry out a clean up,” Ramazan Abdulatipov said.

Residents of the Capsian Sea city have trouble imagining the mayor behind bars.

“Every time I see the latest television news bulletin, I think I’m dreaming,” an accountant at a private company who gave her name as Madina said. “If someone had told me a few days ago this would happen, I would have called him crazy.”

“I AM STRONGER”

Putin himself rose to power after launching the second of two wars in Chechnya next to Dagestan, and presents himself as the man who restored order in Russia after the chaos that followed the Soviet Union’s collapse.

His main tactic for imposing control over the restive Muslim provinces of the Caucasus has been to provide lavish financial and political backing for handpicked local strongmen, who brook little dissent, wield personal authority over ruthless security forces and maintain business empires.

Dagestan’s economy is about three-quarters subsidised by Moscow. Most people in the region believe the funds go straight into the pockets of local officials who cruise Makhachkala in expensive cars guarded by armed musclemen.

In an interview with Reuters at his plush penthouse office a few weeks ago, Amirov boasted he had survived 15 assassination attempts, including one that left him wheelchair-bound in 1993.

“Various armed groups wanted to wipe out the mayor, but what can you do? They didn’t succeed. I am stronger,” he said.

Rights groups say police in Dagestan routinely torture their prisoners. But unlike in neighbouring Chechnya, the heavy hand has not broken the back of the insurgency.

According to the Caucasus Knot website which tracks the unrest, 67 people were killed and 41 wounded in the first three months of this year. Attacks like a suicide bombing that killed four people in Makhachkala last month are so common residents say they are inured to the violence.

Konstantin Kazenin, a journalist and expert on the North Caucasus, said Amirov ran a “deeply-layered, intricate, totalitarian business empire” whose unravelling could unleash a violent power struggle among his former allies and foes.

“For many of the key figures in this empire, Amirov’s position as mayor was key not only to their personal property, but also to their security and freedom,” he said. “So if no special decisions are taken, and no deals are made, the urban economy of Makhachkala may well face great upheaval.”

Federal investigators say Amirov, 59, was arrested with 10 other suspects over the 2011 killing of a senior state detective. They are also looking into accusations of links to drug trafficking and other high-profile crimes for which he could face life in prison.

Officials say the murder charges are based on the testimony of the leader of an insurgent group captured after a firefight just last week. However, a spokesman for investigators said the arrest had been under preparation for two years.

Whatever the case’s substance, Amirov’s downfall could not have taken place unless the Kremlin turned against him.

“The rules of the game are changing radically,” said Denis Sokolov, head of the RAMCOM Center for Regional Socio-Economic Studies. “It’s a risky game because the mayor of Makhachkala was one of the middleman via whom Moscow ruled the region.”

“People at the top were probably displeased with his methods, but, nevertheless, he was their middleman.”

Since the collapse of the Soviet Union in 1991, Dagestan’s factories have fallen into disrepair. Bribes drive up the cost of state services. Unemployment is rife. Misery and anger at the local authorities feed the insurgency.

“Putin realized that unless measures are taken to improve the quality of governance, the situation countrywide is going to explode. In Dagestan it is already exploding,” said Ekaterina Sokirianskaya of the International Crisis Group think tank.

“The decision was taken in the Kremlin to go after one of the really notorious figures ... If they don’t go after others, it will give the wrong signal that this is just a change in decoration.”