BUDAPEST - Hungarian police fired volleys of tear gas at a few hundred violent far-right protestors who were staging an illegal demonstration in Budapest on Thursday.

Protestors armed with stones and bottles had earlier attacked reporters, according to Hungarian news agency MTI whose correspondent was injured.

Hundreds of others, waving the historic Hungarian "Arpad" flag that has become a symbol of the far-right here, were on their way to the demonstration.

The protesters had gathered near a police precinct in downtown Budapest after receiving news that one of their comrades, wanted for inciting street riots in September and October, had been detained.

Those clashes were triggered by the leak of an audio tape in which Socialist Prime Minister Ferenc Gyurcsany admitted he misled voters on the economy to win parliamentary elections.

Intelligence services have been warning for several weeks that extremists were stocking up on weapons and planning coordinated attacks on Thursday, a national day marking the country's 1848 revolution against Habsburg rule.

Airspace over parts of the city was closed and more than 100 closed-circuit cameras were installed around the capital over the past few days.

The day is a traditional occasion for political rallies.

Earlier, the main right-wing opposition Fidesz party staged an anti-government rally with an estimated 200,000 sympathizers, including several thousand far-right supporters.