Kazakhstan on Sunday elected the hand-picked successor of former president Nursultan Nazarbayev with 70% of the vote, according to exit polls, as police in the Central Asian republic arrested hundreds of opposition protesters.

The victory of career diplomat Kassym Jomart-Tokayev was widely expected after he was granted the blessing of powerful Nazarbayev, who had led the former Soviet republic for the last three decades.

Turnout in the election was around 77%, according to the Central Election Commission.

Tokayev, 66, took just over 70% of the vote, according to the government-approved “Public Opinion” pollster. His nearest opposition rival Amirzhan Kosanov garnered around 15%.

But the day was marked by the largest demonstrations the Muslim-majority country has seen in three years, as protesters urged a “boycott” of what they said was a fixed election.

The build-up to the vote saw an intensifying crackdown on the opposition with courts sentencing protesters to short periods in jail and police raiding activists’ homes.

The Interior Ministry said around 500 people were arrested on Sunday, with Deputy Minister Marat Kozhayev blaming “radical elements” for holding “unsanctioned” rallies.

Two AFP journalists were among those detained in the largest city, Almaty, where police broke up a protest involving several hundred people.

Nazarbayev’s announcement in March that he was stepping down from the presidency and naming Toyakev interim leader shocked Kazakhs who had lived under his rule since the Soviet era.

But the 78-year-old, who turned the country of 18 million people into an energy powerhouse while governing with an iron fist, is still expected to exercise power from behind the scenes.

As he voted, Tokayev told reporters in the capital Nur-Sultan, formerly Astana, that Nazarbayev was “still in power in the capacity of chairman of the security council… and other capacities.”

– with reporting by AFP