"Russia's record on human rights is also an issue at the summit.
A protest by opposition groups has been allowed to go ahead in Samara, but leaders, including Mr Kasparov, had their passports and tickets removed by police as they tried to board a plane at Moscow airport.
Several foreign journalists were also reportedly prevented from travelling.
Organisers said they were not expecting more than 1,000 people to attend, and a demonstration by
pro-Kremlin groups will go ahead simultaneously."
Again Nazi methods
BBC NEWS | Europe | Rows overshadow EU-Russia talks