Hundreds of demonstrators called for Russia's leaders to resign at two protests in Moscow on Sunday, the latest in over a dozen rallies this weekend against the government's handling of the economic crisis.



Around 50 drivers and auto sector workers protested near the Kremlin against import tariffs on used cars, a measure designed to protect the domestic auto sector but which has provoked anger among consumers, particularly in the far east.



'Let the senators drive Ladas, and Putin ride a handcart,' read one banner unfurled by protesters in temperatures below minus 20 degrees Celsius (minus 4 Fahrenheit).



Some of these protesters later joined a crowd of 250 people commemorating the deaths of prominent human rights lawyer Stanislav Markelov and trainee reporter Anastasia Baburova, who were shot dead in broad daylight last month in central Moscow.



Anti-war activist Anna Karetnikova, a friend of the slain lawyer and of prominent reporter Anna Politkovskaya, who was murdered in 2006, told the crowd that the double murder was likely carried out on behalf of the Kremlin.



The crowd responded by chanting: 'No to political murder.'



In recent years authorities have regularly refused opposition groups permission to protest in the centre of Moscow, and sent riot police to break up unsanctioned rallies.



By sanctioning some protests, including the two on Sunday,the Kremlin appears to have acknowledged a need for the public to express discontent over hardships.



President Dmitry Medvedev met on Thursday the editor of Novaya Gazeta, the newspaper where Baburova worked. He expressed his condolences over the death.



Prime Minister Vladimir Putin, former president and Medvedev's mentor, faces a serious test of his ability to quellsocial discontent as Russia heads into its first recession in a decade.



Half a million Russians lost their jobs in December as the economy, fuelled for a decade by high commodity prices, began tocontract. Unemployment is at a 2-1/2-year high of 7.7 percent.



Galina, a pensioner who stood through the second hour-long demonstration in Moscow, but refused to give her last name, said she was to help call for new leadership.



'The government is dealing with its own business, which has nothing to do with the interests of the people,' she said.



The used car tariffs have provoked anger among consumers, many of whom prefer to buy foreign models, as well as autoworkers employed by foreign car makers.



Riot police in Vladivostok -- a major importer of used Japanese cars -- detained over 100 people in an unsanctioned rally in December. Most of the weekend's rallies were peaceful.



'This decision has split the nation in half,' said the head of the opposition Yabloko party, Sergei Mitrokhin. 'The government only has regard for one group of people, and that is the oligarchs.'