Choi Yuen Tsuen supporters have turned up the heat by staging a protest aboard MTR trains and showing passengers video clips of an earlier confrontation between an activist and security guard.

The protest revolved around an incident on January 20, when activist Chu Hoi-dick, 33, was flung to the ground and injured while scuffling with an MTR guard during a protest to stop demolition of the village in Shek Kong to make way for the high-speed railway to Guangzhou. Both the guard and Chu have lodged police complaints.

Yesterday, 20 post-80s protesters boarded trains on the Tsuen Wan-to-Central run, playing two different video clips simultaneously on iPads and notebooks, with the left side of the screen showing the version provided by the activists, and the MTR Corp's version on the right.

"By playing the clips on the train, we aim to let more people know what happened that day so they can make their own judgment," said Jer Choi Tsz-kwan, a member of the Post-80s Boys and Girls group.

The protesters also handed out flyers, which cited judo masters as saying the maneuver the guard allegedly used on Chu was not for self-defense. The guard is said to have used a hip throw called uki goshi.

With banners proclaiming "Hurray to violence" and "Recruit MTR uki goshi masters," two protesters demonstrated the throw in the concourses of Admiralty and Central stations.

"The protest is to poke fun at the MTRC," Choi said.

"With so many unknown [judo] masters in the MTRC, we came here to recruit some."

The move won a measure of sympathy from passengers.

A young commuter said she disapproved of the guard's action, but felt the activists should stage their protest outside.

Another, a Richard Chan who is in his 30s, said he found the protesters' action acceptable and not intrusive. He also found the guard's throw disturbing.

MTR staff at Admiralty tried to get the activists to stop, saying they may disturb passengers. The protesters refused, but took off for Central about 10 minutes later.

There, police were called in by the MTRC. A sergeant said protesters should have applied for a permit before staging a demonstration in the MTR area.

According to MTRC by-laws, the corporation can ask people to stop acts that disturb passengers.

An MTR spokeswoman wouldn't say if the protesters had breached bylaws. But she apologised to any passengers who may have felt disturbed.

Protester Chan King-fai said the right to stage protests is protected by the Basic Law.