Russian Facebook users have poured scorn on a promise by Russian President Dmitry Medvedev to investigate reports of electoral fraud.

At least 7,000 comments had appeared under his post by 20:00 GMT on Sunday, a day after the biggest anti-government protests since Soviet times. An early random sample showed the comments were equally divided between hostility, support and neutrality. Mr Medvedev prides himself on using social media. He recently suffered an embarrassment on Twitter. Having already conceded that some violations of electoral law had taken place at the parliamentary elections last Sunday, he went on Facebook to say he had issued instructions for all official reports on the conduct of the polls to be checked. It was his comments on Saturday's election protests - some 50,000 people turned out in Moscow alone - which drew particular anger.