Russia's domestic intelligence service yesterday summoned Garry Kasparov, the former world chess champion, for questioning over possible violations of anti-extremism laws in what analysts said could be an attempt to close down his opposition political group.

Mr Kasparov was among 170 people detained by police last Saturday as riot police suppressed a rally by the opposition Other Russia coalition - of which Mr Kasparov's group forms a part. He was later released after being fined Rbs1,000 ($39, €28, £19) for public order offences.