Four young men have pleaded guilty to rioting during the police siege of a university at the height of the 2019 anti-government protests in Hong Kong, with a defence lawyer saying in mitigation that one of them later developed post-traumatic stress disorder after being tortured in “KK Park” – a notorious scam compound in Myanmar.

The District Court on Monday heard guilty pleas from Cheung Chung-yiu, Cheung Chin-ming, Chan Chun-hei and Chan Yuen-ming, who were aged between 16 and 27 at the time of the November 2019 riots at Polytechnic University.

The four were among more than 1,300 protesters arrested in connection with the unrest inside and outside the campus. While at least 200 people were charged with rioting and sentenced before 2024, these defendants were rearrested in June that year and formally charged with one count of rioting.

According to the prosecution, Chan Yuen-ming wandered around the university campus and took several unidentified glass bottles from a laboratory during the incident.

Defence counsel Steven Kwan Man-wai told the court on Monday that the defendant, now 33, suffered from post-traumatic stress disorder after being tortured and detained in “KK Park”, a Chinese-run “fraud factory” on the Myanmar-Thailand border where thousands were held as forced labourers. He was released in 2022.

Kwan added that Chan Yuen-ming did not stay long at the university, urging Judge Edmond Lee Chun-man to consider that imprisonment would have a harsher impact on him than on others.