Police fired tear gas at protesters who disrupted morning trains onTuesday for the second day in a row as Hong Kong’s five months of anti-government demonstrations turned increasingly violent.

Protesters and police faced off in and around several university campuses as classes were cancelled.

Subways were partially shut down, and passengers on one commuter train disembarked short of the station and were escorted along the tracks in video shown on Hong Kong television.

Recent weeks have been marked by escalating vandalism against shops and train stations along with assaults by both protesters and pro-Beijing supporters on the other side. The demonstrations have divided the former British territory (Vincent Yu/AP)

Hong Kong leader Carrie Lam, speaking to news media after a weekly meeting with advisers, called the blocking of the morning commute “a very selfish act.”

“People from different sectors in society are holding fast to their positions and refusing to concede to violence or other radical actions,” she said.

“I hereby express my gratitude to those who are still going to work and school today.”

On Monday, a police officer drew his gun during a struggle with protesters, shooting one in the abdomen.

A very selfish act

In another neighborhood, a person was set on fire after an apparent argument.

The Hong Kong hospital authority said both were in critical condition.

Video of another incident showed a policeman on a motorcycle riding through a group of protesters in an apparent attempt to disperse them.

Police say those events are being investigated but defend the officers’ actions as necessary for their own safety.

Lam pledged Monday to stop the violent protests in comments suggesting harsher legal and police measures could be coming.

The protests initially began over a proposed law that would have allowed criminal suspects to be extradited to mainland China, where they could face opaque and politically sensitive trials.

Activists saw the bill as another sign of an erosion in Hong Kong’s autonomy and civic freedoms, which China promised would be maintained for 50 years under a “one nation, two systems” principle when the former British colony returned to Chinese control in 1997.