BEIJING - (AFP) - China said Wednesday that it had lodged an official complaint with Britain over an altercation between its diplomats and a Hong Kong protester at its consulate in Manchester, northern England.

British police said that a group of men left the consulate during a demonstration at the end of last week, dragged a demonstrator into the consulate and assaulted him.

The incident sparked widespread condemnation in Britain and caused a diplomatic dispute, prompting the British Foreign Office to summon a senior diplomatic official.

Beijing said Wednesday that its diplomats were not to blame for the altercation.

"Due to malicious harassment by outlaws and illegal entry into the Chinese Consulate General in Manchester, this has injured Chinese personnel and threatened the security of Chinese buildings," Foreign Ministry spokesman Wang Wenbin told reporters at a routine press conference.

He added that China had "expressed its displeasure" to the British authorities and urged London to do more to protect its diplomats on British soil.

Beijing had earlier announced that the protesters had "illegally entered" the consulate, which was not mentioned in the text of an official foreign ministry report Wednesday.

Police in Manchester said they were conducting an investigation into the incident, which the prime minister's office deemed "extremely troubling" and drew condemnation from British lawmakers.

The man in question, in his 30s, sustained injuries and spent the night in hospital, according to police.

The newly appointed chair of the UK Parliament's Foreign Affairs Committee, Alicia Cairns, accused Chinese Consul General Zheng Xuan, a senior Chinese diplomat in Britain, of being on the scene and "tearing up posters" during a "peaceful protest".

China has not responded to these accusations.

The demonstration was held in front of the Chinese Consulate in Manchester on Sunday, the opening day of the Communist Party Congress in Beijing, which is expected to coincide with a third term for President Xi Jinping.