London, Berlin, Amsterdam, Brussels and other cities with large immigrant populations are on the lookout for any signs of copycats of the urban violence that has engulfed Paris and other French cities, destroying cars, shops and schools.
So far there have been only isolated reports of wanton violence beyond France's borders - five cars set on fire in Berlin on Sunday and six in the western German city of Bremen. Leaders in Britain, Germany and elsewhere point to unique circumstances in France that make it less likely that they will face similar rioting. But there are nevertheless potential powder kegs in countries with large foreign populations.
"Everybody's concerned at what is happening," British Prime Minister Tony Blair said on Monday. "I send every support to the French government and to the French people in dealing with the situation. You should never be complacent about these things, although I think our situation is in some ways different."
The Paris violence was sparked by frustration among ethnic minorities over racism, unemployment and harsh treatment by police. Many of the rioters are French-born citizens of Arab or African origin. Many feel trapped in the drab suburbs, built in the 1960s and 1970s to house waves of immigrant workers.
May Day riots hit Berlin every year on May 1 and luxury cars in Kreuzberg, once a haven for squatters now being turned into a high-rent district, are occasionally torched by leftist extremists. But there is no ethnic element to the attacks.
"There is no way violence as intense as in France would hit Germany or most other European countries," Nadeem Elyas, chairman of the Central Council of Muslims in Germany, told Reuters. Some 3.2 million Muslims live in Germany, making it the second largest Muslim community in Europe after France.