Brussels, Belgium - Belgian police arrested 154 people for taking part in a banned protest in Brussels against "the Islamisation of Europe", on the anniversary of the September 11, 2001 attacks.
"There were 154 administrative arrests," said city mayor Freddy Thielemans, who imposed the ban last month amid fears that the demonstration could enrage the capital's immigrant community.
Under Belgian law, they could be held for up to 24 hours.
A spokesman for Belgium's far-right Vlaams Belang party said two of its leaders, Frank Vanhecke, who is also a member of the European Parliament, and Filip Dewinter, were among those arrested.
Police said later that the two would be charged on allegations that they attacked the driver of the armoured car they were transported in.
Two other members of the European Parliament were also arrested.
Earlier, a journalist at the scene in the capital's European quarter saw police attach plasticuffs to would-be demonstrators, many of them with shaved heads and wearing Belgian nationalist symbols, and lead them off.
No street violence was reported.
"I'm shocked. I thought we lived in a democratic country," said Anders Gravers, one of the organisers from Stop the Islamisation of Europe (SOIE).
Dutch group 'No Sharia Here' and Germany's 'Pax Europa' also took part.
Police were out in force around the European Union's main institutions, given that the demonstration was effectively illegal.
Requests to hold counter-rallies had been submitted by a number of groups, including the Arab European League, but they too were rejected.
Organisers had hoped to bring thousands onto the streets of Brussels on the anniversary of the September 11 attacks.
"We think that six years ago, in 2001, it wasn't [US President George W] Bush that brought down the twin towers but the Islamists, and we want to stop it," said Stephen Garsh, an SOIE co-founder.
Mr Gravers did manage to hand a petition with some 10,000 signatures condemning the mayor's ban to Gerard Batten, a deeply eurosceptic British member of the European Parliament, who promised to hand it on to Thielemans.
The head of the Council of Europe - a mainly human rights watchdog based in Strasbourg, France and not an EU institution - branded the protesters bigots and said they were a threat to Europe's values.
"It is very important to remember that the freedom of assembly and expression can be restricted to protect the rights and freedoms of others, including the freedom of thought, conscience and religion," secretary general Terry Davis said.