London (CNN) Hong Kong's Secretary of Justice Teresa Cheng was injured Thursday after an altercation with protesters in London.

According to London Metropolitan Police, a woman was taken to hospital by ambulance after "suffering an injury to her arm." The force told CNN it was investigating an alleged assault and "no arrests had been made at this stage."

A video on social media appears to show Cheng surrounded by a crowd as she was walking to a lecture at London's Chartered Institute of Arbitrators (CIArb). It then shows her suddenly on the ground.

In this video screengrab, Hong Kong's Secretary of Justice Teresa Cheng is confronted by protesters in London.

The incident comes amid renewed protests in the semi-autonomous Chinese city, which has been gripped by almost six months of anti-government protests originally sparked by an extradition bill with China. As Justice Secretary, Cheng was one of several senior officials, along with Chief Executive Carrie Lam, closely linked to the now-shelved bill.

According to Hong Kong public broadcaster RTHK , Cheng was in the UK "on a trip to promote Hong Kong as a venue for dispute resolution."

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