Google has removed YouTube advertisements by Russian anti-Putin campaigner Alexei Navalny ahead of regional elections in the country.

Mr Navalny appeared in the ads encouraging Russians to take part in demonstrations and protests against raising the retirement age.

Around 50 of his supporters were detained ahead of the rallies over the weekend, according to local media.

Mr Navalny's representatives have argued that the removal of the ads from YouTube was "political censorship", but Google has claimed that it required advertisers to act in accordance with local laws.

Russian authorities say the adss are illegal under the country's electoral laws, which prohibit campaigning within 48 hours of the polls opening.


Dozens detained by police in Russia

In a statement, Google-owned YouTube said it considered all all valid requests from governmental bodies, adding: "We require advertisers to comply with local law and our general advertising policies.."

Earlier this year, proposals were announced to increase Russia's retirement age for men from 60 to 65, and from 55 to 63 for women.

Many Russian families, especially in rural areas and small towns, have relied on pensions during times when young people struggled to find stable jobs.

The policy caused Vladimir Putin's poll ratings to take a hit of around 15%, with the Russian president later softening his stance.

In cities such as Dzerzhinsk, where life expectancy is rising but is still low, some are worried they will not live long enough to retire.

The first rallies against the policy change occurred in eastern Russian on Sunday morning, with protesters walking through Moscow holding red balloons escorted by police.

Why many Russians will never retire

Demonstrations also took place in Saint Petersburg and Moscow on Sunday afternoon.

"Putin and his government have plundered the budget for the past 18 years," Mr Navalny's team said in a pre-protest statement.

"All that time they assured us there would not in any circumstance be a rise in the pension age. And now they are putting it up.

"The authorities are not listening to people and that means it's time to take to the streets."

Mr Putin makes a point of never mentioning Mr Navalny by name but has suggested he is Washington's pick for the Russian presidency.