Thousands of anti-government protestors, many of them waving the red-and-white-striped "Arpad" flag used by the country's pro-Nazi government during World War II, erected barricades, hurled Molotov cocktails, vandalised cars and broke storefront windows as they rampaged through the capital on Monday.
Socialist Prime Minister Ferenc Gyurcsany said Orban, a former prime minister who lost the past two parliamentary elections to the left, had encouraged extremists with his inflammatory rhetoric and by failing to condemn radicals.
"Radical words result in radical deeds. The leader of the opposition gave an ideology to troublemakers on the streets. The link is obvious," Gyurcsany said in an impassioned speech to parliament. Among a string of inflammatory remarks, Orban said in September that a conservative win in local elections would legitimise an "assault against the government."
On Monday, his Fidesz party, instead of condemning the rioters, defended them by saying police, who shot rubber bullets and tear gas against protestors, had used "brutal and inexplicable force."
The government said Tuesday in a statement that 167 had been injured, including 17 police officers, while 131 were detained in the riots which overshadowed the 50th anniversary of the Hungarian uprising against Soviet rule.
Orban organised anti-government protests for over a month, after a recording was leaked in mid-September in which Gyurcsany was heard saying he had lied to voters about the dire state of the economy to win re-election in April.
The initial protests by extremists set off riots over three nights that left hundreds injured in the worst violence here since the end of communism in 1989.
The protests followed an ultimatum from Orban for Gyurcsany to resign after losing October 1 local government elections or else face mass street demonstrations.
"The extremists participating in riots do not have a name but they do have a colour," Peter Balazs, a political science professor at Central European University, told AFP, in reference to the pro-Nazi red-and-white flags.
"These are aggressive far-right supporters and football hooligans," he said.
Extremists waving "Arpad flags" are a regular feature at Fidesz protests, underlining the solidarity between the two camps.
"The 'Arpad flag' has since 1944 become synonymous with the fascist Arrow Cross regime under which tens of thousands were shot into the Danube and millions were held in fear," Gabor Kuncze, president of the junior coalition liberal Free Democrats party, said in parliament.
"Why does (Fidesz) not say during its rallies that these flags have no place there, that those protestors should get the hell out of there? What we see is not only the responsibility of Fidesz but the tactics of Fidesz," Kuncze said.
Orban, who sought the support of far-right voters during April's election, is unlikely to distance himself from the extremists, according to analysts.
"Moderate western European parties symbolically and unambiguously distance themselves from far-right parties. Fidesz refuses to do this because they will support (it) in elections," political analyst Attila Agh said on public television.

Copyright AFP (Agence France-Presse), 2006