Parts of the city came to a standstill as supporters of the nationalist Ataka party marched through the streets chanting anti-government slogans.

Ataka party leader Volen Siderov told the crowd that ethnic minorities such as Turks and Gypsies should not be allowed into the Bulgarian government.

Ataka received eight percent of the vote in last year's elections.

It holds 21 of the 240 seats in parliament. Loudspeakers broadcast the music from the film Star Wars as the nationalists marched past government buildings chanting slogans calling for early elections.

Mr Volen Siderov demanded the government revise recent privatisation deals and tackle organised crime.

"Let's give Bulgaria back to the Bulgarians," Mr Siderov told the crowd. "Bulgaria is not yet free. Bulgaria is still under Turkish rule."