Russian President Vladimir Putin has reshuffled the jobs of top officials ahead of elections in September, but the Kremlin has said the two events are unconnected.

"It is a regular rotation conducted by the head of state, which is aimed at increasing effectiveness in some cases, and at fixing problems in other cases when the situation is not satisfactory," the president's spokesman Dmitry Peskov said.

Seven governors, one ambassador and presidential envoys have been removed from their posts as well as the head of Russia's customs service. At least six of them have been given other jobs.

"The Russian system means that you can almost never fire anyone," said Ekaterina Schulmann, a political analyst. "You have to find another place for someone unless the person is arrested. So you have to move them from one place to the other like in a game. This is a complicated process and makes it likely that several decisions will be made at once."

In Russian you can't fire anyone, says Schulmann

She points towards the aging older generation as one of the reasons for this reshuffle, saying the children and relatives of high-ranking officials are now of an age where they can occupy key positions.

There is, she noted, a "generational change taking place in an environment where there are no mechanisms for this change."

Sometimes, she added, "criminal charges, or the threat of criminal charges" are used to remove incumbents from their positions.

Customs scandal

Prime Minister Dmitry Medvedev signed off on the resignation of Andrei Belyaninov, the former head of the customs service, on Thursday. He is a former KGB agent who served alongside Vladimir Putin in East Germany in the 1980s. His resignation was accepted after security services searched his office and house following allegations regarding smuggling of high-end alcohol.

Andrei Belyaninov is alleged to have smuggled alcoholic beverages

Reports in Russian state media said investigators uncovered about $400,000 in cash during a search of his home.

Belyaninov has not been charged but has been replaced by Vladimir Bulavin. Bulavin also has connections to Russia's security services as he was a former deputy chief in the FSB.

Another FSB official was shifted to govern the region of Kaliningrad. Kaliningrad is an exclave, situated between Poland and Lithuania. It is strategically important for Russia because it is the home of the country's most westerly military base and the Baltic Sea Fleet.

The president's spokesman said the appointment of ex-military and security personnel as governors of both the Kaliningrad and Yaroslavl regions was Vladimir Putin's "personal decision."

Government spokesman Dmitry Peskov called the moves 'regular rotations'

"He demonstrated that he trusts them and believes that they are the right people who have the potential to continue these regions' development," Dmitry Peskov said.

Vladimir Putin has long surrounded himself with people from the security services and himself served in the KGB.

Ekaterina Schulmann says the appointment of security officials to high posts "is the most characteristic feature of the regime. This demonstrates that the regime is more or less as it has been for the last 15 years."

She adds, however, that a new development is the promotion of people "not just from the secret services but also the president's personal guard, including the governors now of Tula, Krasnodar and Kaliningrad."

During the reshuffle, President Putin also consolidated the 'Crimean Federal District' into the Southern Federal District which was already in existence. Russia annexed Crimea from Ukraine in 2014 - a step that was condemned as a breach of international law.