There has been an attack on the French consulate in Zurich. Police on Monday confirmed local radio reports that devices, similar to fireworks, had been hurled at the entrance to the building during the night.
Police said that no one was injured in the attack, which caused minimal damage to the consulate on the city's Mühlebachstrasse.
Zurich city police spokesman Marco Cortesi said the incident was being taken seriously and the hunt was on for the perpetrators.
The private radio station, Radio Z, reported that it had received a claim of responsibility from a group calling itself "Revolutionary Perspective". The radio said the letter expressed solidarity with members of the Spanish underground organisation, Grapo, who are imprisoned in France.
Revolutionary Perspective - a left-wing extremist organisation - earlier this year claimed responsibility for two minor bomb attacks on military targets in Bern.
There is growing concern in Switzerland over the recent rise in extremist activities. The head of the federal police, Urs von Daeniken, says that while Switzerland's security is not under threat there is no room for complacency.
swissinfo with agencies