Several thousand Hungarians marched though Budapest on Sunday to demand the resignation of the head of the country's tax office after she was banned from entering the United States over alleged corruption.
Ildiko Vida confirmed last week she was on a US blacklist of six unnamed officials, made public by Washington's charge d'affaires in Budapest last month, who said the US had "credible information" of corruption.
A crowd estimated by an AFP photographer at around 10,000 chanted "We won't pay our taxes to crooks" and "Orban get lost!," referring to Prime Minister Viktor Orban, who has said the US should provide its evidence.
Vida, the first of the six banned officials to go public, has denied the allegations and refused calls to resign.
The bans have further strained relations between Budapest and the US, which have worsened since Orban took power in 2010.
In September, US President Barack Obama criticised Hungary for harassing foreign-funded civil organisations. The charge d'affaires, Andre Goodfriend, said in October that "negative trends" have "rapidly taken hold."Last week, Orban said Washington was wrong to view as a "rapprochement to Russia" Hungary's support for the Russian-backed South Stream gas pipeline project, as well as an expansion by Russia's Rosatom of Hungary's only nuclear power plant.
The crowd Sunday also carried EU and Norwegian flags, protesting against Orban's often anti-EU rhetoric as well as an ongoing bitter row with Oslo over civil organisation funding.
The demonstration, which passed off peacefully, happened soon after massive protests in October against a proposed Internet tax in Hungary forced Orban to backtrack on the idea.
"The Internet protests showed at last, after years of apathy, that people power can work here," one marcher Tamas Hevesi, 50, told AFP.
If Vida and other implicated tax officials don't resign within one week, protestors will be back in greater numbers on November 17, a speaker told the crowd.