Two retired police officers were arrested for allegedly assaulting anti-extradition bill protesters during a clash on Wednesday night at a “Lennon Wall” in Yau Tong, Kowloon.

The two suspects, a 56-year-old man surnamed Kong, said to be a former police officer at Kwun Tong Police, and a 57-year-old man surnamed Yeung, who served in Sau Mau Ping Police Station and is now said to be a security officer, were arrested after they allegedly attacked young protesters near Yau Tong MTR station, Sing Pao Daily quoted an unnamed police source as saying.

The clash broke out when the government supporters tried to destroy messages stuck on the Lennon Wall and forced the protesters to leave – while young protesters wanted to protect it. That led to the arrival of riot police with batons and shields to control the crowd.

According to online video clips, several men who surrounded the young protesters were suspected to be off-duty police. They yelled at the young people, calling them “dogs” and forcing them to leave Yau Tong.

The two former police officers, together with another man were arrested for alleged assault. One protester had to be sent to hospital for medical treatment.

Opponents of the city government’s extradition law created the ‘wall’ by sticking up colorful messages to try to encourage Hong Kong people not to give up their fight against chief executive Carrie Lam and to keep pushing for their demands related to the saga. But not everyone has welcomed the move.

In fact, Lennon Walls in many other places were destroyed over the past few days. Some were destroyed by people who torn down the Post-it notes. And one in Aberdeen was destroyed by fire, while someone splashed urine on one in Tung Chung and excrement on the Wall in Jordan.

Meanwhile, photos surfaced on social media on Thursday with alleged dialogues on WhatsApp by a suspected retired marine police officer. A passenger said he took the photos while traveling on a bus.

The dialogue stated how to destroy the protest sites. One photo showed a member suggesting to give some money to drug abusers to put excrement on a Lennon Wall. Another group member suggested arranging someone with AIDS to carry along a syringe.

A WhatsApp thread said to be from retired marine police on how to hire drug abusers to attack a Lennon Wall. Photo: Facebook

One member suggested posting details about Democratic Party lawmaker James To and his family across the streets in Hong Kong.

The photos also showed suspected police identity numbers and the name of several members. Information disclosed on the online forum was suspected to be from retired marine police officers.

According to Apple Daily, three names displayed on the group matched those of police who received awards and had their names in the government gazette.

Lok Tak-chi, chairman of HK Marine Police Retirees’ Association, admitted that there was a WhatsApp group among its members. Lok said he deleted the messages after reading them – so he could not recall any content.

Lok said that retired police felt frustrated recently as society was no longer calm and they were just venting anger on the instant messaging group. He denied that their members encouraged others to destroy sites set up by the protesters. He said he had told group members to keep calm.

Helena Wong Pik-wan, a Democratic Party lawmaker and former member of the Independent Police Complaints Council, reminded retired police to behave and not to encourage any acts of revenge. She advised the government to ease the tension between police and the general public.

Meanwhile, James To that information the WhatsApp group disclosed was all public information. He said he would take no further action at the moment but would monitor developments, adding that “it could be a channel to vent their anger”.