BERLIN — With visible and vocal far-right protests against foreigners swelling in Germany in recent weeks, Chancellor Angela Merkel forcefully denounced the demonstrations on Monday, affirming that the country has both a special obligation and a desire to welcome anyone in need of sanctuary.

More than 150,000 people sought asylum in Germany in the first 11 months of this year, many of them refugees fleeing the conflict in Syria, straining the country’s ability to house them. In addition, a looming labor shortage means Germany is increasingly attracting immigrants to work here.

“There is freedom of assembly in Germany but there is no place here for incitement and lies about people who come to us from other countries,” Ms. Merkel told reporters on Monday, hours before a group opposing alleged “Islamization” held its ninth weekly protest in Dresden, where attendance has swelled from a few hundred to 15,000 this week.

“Everyone needs to be careful that they are not taken advantage of by the people who organize such events,” Ms. Merkel said. But her warning did not seem to deter the marchers. From 10,000 last week, they again strengthened their presence, despite a week of mounting establishment concern about right-wing opposition to Germany’s open door for immigrants.