Czech police say a group of about 20 unknown attackers set fire to a center that helps refugees in Prague on February 6, just hours after thousands of people staged a protest in the Czech capital against Muslims and immigration.
The attackers stormed the Klinika center that organized a collection of clothing for refugees, and threw Molotov cocktails.
Authorities say at least one person was injured in the attack.
A spokeswoman for Prague firefighters said the fire was extinguished quickly.
Activists who work at the center, a former medical clinic in Prague’s Zizkov district, said the attackers were neo-Nazis.
The anti-Muslim protest staged in front of Prague Castle, the presidential seat, was one of many organized across Europe on February 6 by PEGIDA, a group whose name translates as Patriotic Europeans Against the Islamization of the West.
The group has become a magnet for far-right and anti-immigrant sentiments since it was founded in Dresden, Germany, in 2014.
About 8,000 PEGIDA supporters who took to the streets in Dresden on February 6 faced off against thousands of counterdemonstrators, but a heavy police presence kept the two groups apart.
PEGIDA member Siegfried Daebritz told the Dresden rally: "We must succeed in guarding and controlling Europe's external borders as well as its internal borders once again."
PEGIDA organizers initially said they expected 15,000 people to participate in their Dresden rally.
The counterdemonstration on the opposite side of the Elbe River that divides Dresden gathered about 10,000 people.
In Warsaw, Amsterdam, Birmingham, and cities in France, Latvia, and Denmark, PEGIDA’s anti-Muslim and anti-immigration demonstrations failed to bring more than a few hundred people out onto the streets.
About 200 PEGIDA supporters who tried to hold their first protest in a public square near Amsterdam’s city hall on February 6 clashed with police.
That violence broke out when authorities closed off the area just before the rally was due to begin while explosives experts examined what police described as a “suspect package.”
But in the French port city of Calais on February 6, police used tear gas and clashed with a violent crowd of about 150 anti-immigrant protesters who chanted slogans like: “We must not let Calais die.”
Several far-right demonstrators were detained by authorities in Calais.
The protesters had ignored a ruling by local authorities that bans such demonstrations.
Calais has become one of the focal points for Europe’s migrant crisis because thousands of immigrants have gathered there and are living in destitute camps while waiting for a chance to slip into Britain though the Channel Tunnel.