Denmark's most famous landmark, 'The Little Mermaid', is seen after unknown culprits wrote "Free Hong Kong" with graffiti on the sculpture, in Copenhagen Reuters

COPENHAGEN (Reuters) - Unknown vandals have scrawled "Free Hong Kong" on Denmark's most famous landmark, "The Little Mermaid", a bronze statue that is especially popular with Chinese tourists.

The 107-year-old sculpture, which depicts the little mermaid from 19th-century Danish author Hans Christian Andersen's tale of the same name, is perched on a rock by a waterside promenade.

More than one million tourists visit the Little Mermaid every year and it has been defaced and damaged several times, twice suffering decapitation.

Hong Kong has been hit by months of pro-democracy unrest against Chinese rule.

(Reporting by Stine Jacobsen; Editing by Mark Heinrich)