Unknown vandals have scrawled "Free Hong Kong" below 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.
On Monday (local time), Hong Kong chief executive Carrie Lam said the Chinese-ruled city's strengths as a global financial hub have not been undermined by months of pro-democracy protests.
Lam told a financial forum in Hong Kong that she was confident the city will bridge divisions, and realise its goals of a reunited community and "flourishing" economy.