BERLIN - Rights groups and opposition leaders called for a strong turnout at planned protests against Russian President Vladimir Putin when he arrives in Germany for a trade fair Sunday.

Activists and critics said Putin should be held to account for a recent crackdown on non-governmental organisations promoting democratic reforms in Russia during his brief stay in the northern city of Hanover.

“I think it is good that the Greens and other groups plan to demonstrate today in Hanover against Putin’s policies and show him that we do not agree with his repression of civil society in his country,” a leader of the opposition Greens party, Claudia Roth, told the Bild am Sonntag newspaper.

Putin, who served as a KGB agent in communist East Germany, will join Chancellor Angela Merkel at an industrial trade fair where Russia is this year’s partner country.

Despite lucrative German-Russian trade ties, valued at about 74 billion euros ($96 million) in 2012, mounting concerns in Europe about the state of human rights in Russia threatened to cast a long shadow over the gathering. Organisations including Amnesty International have called a rally outside the fairgrounds ahead of Putin’s arrival.

In an interview Friday with German public television, a defiant Putin said the controversial searches of NGOs’ offices were justified as Russian authorities need to keep tabs on foreign groups involved in politics.

A spokesman for Merkel said the issue would certainly figure in talks between the two leaders, whose personal rapport is widely reported to be cool. The human rights spokesman for the parliamentary group of Merkel’s Christian Democratic Union, Erika Steinbach, urged the chancellor to place democratic values ahead of economic interests.

“Despite strong business ties, we can’t close our eyes to the dismal human rights situation in Russia,” she told Bild am Sonntag, echoing a call from Human Rights Watch last week.

Germany, Europe’s biggest economy, is heavily dependent on Russia for gas and oil, while Russia’s appetite for German products has surged over the last decade.

But Merkel has not shied away from public criticism of Russia. During a visit to Moscow in November she angered Putin by questioning prison sentences against members of the feminist punk band Pussy Riot.