Tokyo ? A foreign man was spotted swimming naked Tuesday in the moat of the Imperial Palace in Tokyo, sparking a police and fire service operation to apprehend him.

About 50 members of the Marunouchi Police Station and fire service were mobilized in pursuit of the man, some of them in boats, as he swam around the moat.

A crowd of about 300 bemused passers-by gathered to take in the rare sight of a nude foreigner thrashing about in the moat and watched him as he clambered out of the water onto a path, from where he hurled stones at police and firefighters before fleeing. It took police officers about 1 1/2 hours to capture and subdue the streaking man as he tried to climb up a stone wall.