China condemned on Friday an attack on the city's justice secretary in London, the first direct altercation between demonstrators and a government minister during more than five months of often violent protests.
Secretary for Justice Teresa Cheng, who was in London to promote Hong Kong as a dispute resolution and deal-making hub, was targeted by a group of protesters who shouted "murderer" and "shameful".
A statement by the Hong Kong government said Cheng suffered "serious bodily harm" but gave no details.
Video footage of the incident showed Cheng falling to the ground.
China's Embassy in the Unuited Kingdom said Cheng had been "besieged and attacked by anti-China and pro-independence activists" who had organised online, and that she had hurt her hand when she fell.
It called on the British police to investigate the incident and to strengthen security for Chinese officials and institutions in the country.
"Ending violence and restoring order is the paramount task in Hong Kong," the Embassy's spokesman said in a statement. "The central government of China firmly supports the (Hong Kong) government in administering Hong Kong according to law, firmly supports the Hong Kong police in enforcing the law and firmly supports the judicial organ in bringing criminal offenders to justice in accordance with (the) law."
Hong Kong's government also condemned the incident.
Violence brings Hong Kong to 'brink of total breakdown': Police
"The secretary denounces all forms of violence and radicalism depriving others' legitimate rights in the pretext of pursuing their political ideals, which would never be in the interest of Hong Kong and any civilised society," it said in an earlier statement.
The attack came amid escalating violence in Chinese-ruled Hong Kong, where a student protester died earlier this month after falling from a parking lot during demonstrations.
Street cleaner killed
A 70-year-old street cleaner, who videos on social media showed had been hit in the head by a brick, died on Thursday, authorities said.
The Food and Environmental Hygiene DepEmbassrtment expressed profound sadness on Friday at the death of the man and said it was providing assistance to his family.
Protesters walk through barricades of bricks on a road near the Hong Kong Polytechnic University in Hong Kong. Protesters have sought to paralyse the city throughout the week. [Kin Cheung/AP Photo]
Anti-government protesters continued their blockade of parts of the city for a fifth day on Friday, forcing schools to close and blocking some highways as students built barricades in university campuses and authorities struggled to end the violence.
The protests escalated in June over a now-scrapped extradition bill that would have allowed people to be sent to mainland China for trial. They have since evolved into calls for greater democracy, among other demands.
Cheng, embattled Hong Kong leader Carrie Lam's chief legal adviser, played a key role in pushing forward the proposed extradition bill that ignited the protests.
The months-long protests have plunged the former British colony into its biggest political crisis in decades and pose the gravest popular challenge to Chinese President Xi Jinping since he came to power in 2012.
Hong Kong is also expected to confirm on Friday that it has fallen into recession for the first time in a decade amid concerns the economy could be in even worse shape than feared as a result of the anti-government protests.