Updated

Thousands of people have gathered in the eastern German city of Dresden for the latest in a series of anti-Islam demonstrations that have alarmed the country's politicians.

Police estimated that some 17,500 people attended Monday's rally by the group calling itself Patriotic Europeans against the Islamization of the West, or PEGIDA — organized this week as a carol-singing gathering in front of the Semperoper opera house.

That would make it the biggest gathering since the weekly protests started in October. An estimated 4,500 people demonstrated in Dresden against PEGIDA, while some 12,000 protested against it in Munich.

PEGIDA'S organizers insist they are protesting only against extremism and not against immigrants or Islam itself, but the demonstrations have received support from far-right groups, prompting concerns that anti-foreigner sentiment might be rising.