China has accused Danish politicians of violating "the basic norms governing international relations'' in a dispute over a Hong Kong opposition activist.
Ted Hui, a former lawmaker, visited Denmark this week after receiving an invitation from Danish lawmakers to travel to the Scandinavian country.
The pro-democracy activist was arrested in Hong Kong in May over a protest in the city's Legislative Council but had obtained a visa to make the trip to Europe.
Chinese foreign ministry spokesperson Hua Chunying said the action of unnamed lawmakers "damages Denmark's image as a country that has always emphasized the rule of law".
"We are firmly opposed to any person, organisation, or country interfering in Hong Kong affairs in any way, interfering in Hong Kong's judicial sovereignty, and shielding illegal criminals in Hong Kong," Hua said at a daily briefing on Friday.
Hong Kong has become a major flashpoint in China's foreign relations following the suppression of anti-government protests in the city last year.
In June, Beijing imposed a National Security Law, which critics say amounts to China betraying its promise to allow Hong Kong to retain its separate political and civil rights.
"I want to emphasise that China is a country under the rule of law and Hong Kong is a society under the rule of law," said Hua Chunying on Friday.
"Where there are laws, they must be followed, and violations must be investigated."
Since the start of the anti-government demonstrations in June 2019, Hong Kong police have made more than 10,000 arrests, most recently prominent pro-democracy figures including activists Joshua Wong and Agnes Chow, as well as outspoken media tycoon Jimmy Lai.
Along with Hong Kong, China has previously tangled with European nations over human rights, Taiwan, and trade.