An explosion at the Italian Cultural Institute in the Spanish city of Barcelona has lightly injured a policeman and killed a sniffer dog.

The blast happened as a bomb disposal team was examining a suspicious metal coffee pot which staff had spotted at the building's entrance on Tuesday.

The Italian foreign Ministry said a home-made bomb had caused the blast.

Spanish police cordoned off the area. No group has claimed responsibility for the attack yet.

The Associated Press reports that graffiti was daubed on a wall outside the cultural institute reading "freedom for Italian prisoners" along with a circle with the letter A - the symbol for anarchism.

PHOTO CAPTION

A Catalan policeman (L) talks to a Spanish policeman near the Italian Cultural Institute in Barcelona after an explosion in the building by what appeared to be a rudimentary explosive device, central Barcelona, Spain, July 12, 2005. (REUTERS)