BONN, Germany — The people who live in the trim row houses with well-tended gardens that line the streets of this spa town along the Rhine like to boast of their city’s tolerance, which dates to its time as the capital of West Germany and home to dozens of foreign embassies.
“We used to be a city of diplomats,” said Christa Menden, who owns a flower shop.
But since 1999, when the central government moved to Berlin, the capital of the reunited Germany, the diplomats have gone. Now there is a growing population of Muslim immigrant families, many of whom have moved into the neighborhood of Bad Godesberg, filling many of the houses left empty by the shift in capitals.
Today Bonn, once tranquil, is a volatile cocktail of social tensions between its Muslim newcomers, who include some German converts as well as immigrants from Arab-speaking countries, with some hard-core elements, and a far-right nationalist group that is mounting a growing campaign against them.
Last month, about 200 Muslims, many from other cities, gathered to defend the honor of the Prophet Muhammad after the far-right Pro-NRW party (for North Rhine-Westphalia) threatened to display caricatures of the Prophet during an anti-Muslim rally in front of the King Fahd Academy, an Islamic school built in 1995 by Saudi Arabia’s government.
After the authorities tried unsuccessfully to win a court injunction preventing the display, they parked police vans to block the view of the offending cartoons. But after one of the 30 or so rightists climbed on the shoulders of another to flash the cartoon at the Muslims, who had just finished praying, a shower of rocks and shards from smashed flower pots flew at the police in response.
“They just exploded,” said Robin Fassbender, a prosecutor in Bonn, who has begun an investigation that could yield attempted murder charges against a 25-year-old Muslim protester who sneaked through the police barrier and stabbed three officers, wounding two seriously.
By the time the rioting stopped on May 6, the police said, they had rounded up 109 Muslim protesters.
“They viewed the police as an organ of the state that wanted to insult Muslims by failing to prevent the caricatures from being shown,” Mr. Fassbender said. “That is a different dimension of violence than these officers are used to. They are trained to regularly take stones and broken bottles, but not to be specifically attacked like this.”
Days earlier the same far-right group held a similar protest in another city, Solingen, where the cartoons of Muhammad were also paraded. The police there detained 32 Muslim protesters after they clashed with officers, throwing stones and charging the barriers separating them from the far-right demonstrators.
The violence, which was preceded by a nationwide campaign by Salafists to hand out Korans in cities, has refocused the authorities’ attention on what they call a threat from the conservative Salafist movement.
German’s interior minister, Hans-Peter Friedrich, has vowed to take stronger action against the Salafists. While they account for a tiny fraction of the estimated 4.3 million Muslims living in Germany, he noted, nearly all Islamic extremists known to German security officials, including several charismatic preachers, have links to the movement. They have proved adept at using social media and Internet forums to attract young followers in Bonn and surrounding areas.
The King Fahd Academy, where the clashes with the police took place, stands incongruously in Bad Godesberg, its gold-topped minaret rising against the deep green bluffs of the Drachenfels crag, where legend has it that Siegfried slew the dragon.
The school was intended to offer a traditional Arabic curriculum to children of diplomats stationed in Bonn. The city authorities tried to close the school in 2003 after it emerged that it taught an extreme form of Islam that encouraged a violent rejection of the Western humanistic values enshrined in the German Constitution.
A compromise was reached, and the school has become a magnet for Muslim families. Several hundred move to Bonn each year, and Muslims now make up about 10 percent of the city’s population. Many are wealthy Arabs attracted to Bonn’s outstanding medical facilities.
The Bonn police spokesman, Harry Kolbe, said, however, that the influx had also brought young Muslims with no jobs or diplomas, who clashed with their wealthier peers.
Ms. Menden, whose flower shop sits on a corner opposite the King Fahd Academy, said she was traumatized by watching what had begun as a peaceful protest deteriorate into a street riot beneath her window. At first, Ms. Menden said, young men, many with long beards and traditional Arabic clothing, greeted her politely. She was impressed by how they had laid out their rugs in the center of the street and bent in unison to pray.
But at some point, she said, she noticed that several young men were stuffing their pockets with the small slate chips that lined the garden along her exterior wall. “I went over to fuss at them, and one turned and threw the stones back in my face,” she said. Her husband pulled her inside to safety.
She said it still upset her to know that the stones from her garden were thrown at the police by the very people who moments earlier had greeted her politely. “I do not feel hate, I do not feel fear,” Ms. Menden said. “I feel disappointment.”
Other residents blame the city’s own education system for the troubles. Classes are taught in Arabic at several elementary schools, part of an effort at integration begun in 2003, when several hundred students had to leave the King Fahd Academy.
“Years of work on integration were unraveled in that demonstration,” said Annette Schwolen-Flümann, district mayor of Bad Godesberg.
Less than an hour after the disturbance, residents swept away the dirt and debris from the overturned flowerpots. Many were Muslims who had sought to keep the peace that Saturday afternoon and were themselves struggling to come to terms with the events.
A Muslim woman who gave her name only as Ms. Elbay because, she said, she did not feel comfortable being identified in media outlets, said she has lived behind the parking lot where the rightist group held its demonstration for the past 11 years without any trouble.
“It is difficult for us as Muslims,” Ms. Elbay said. “Our image is always being destroyed. We do our best to try to live a normal life; we send our children to integrated play groups, we have German friends, and then these people come and destroy it,” she said, referring to the Muslim demonstrators who had turned violent.
Ms. Menden insisted that now she struggled to fight back anger whenever a Muslim neighbor greeted her.
Another neighbor, Hans-Peter Weisz, who has lived on the street for 30 years, said his children were frightened that protests would recur there. “You can understand how a hate against foreigners can grow,” Mr. Weisz said, “It’s not good.”