Hong Kong on Thursday witnessed rounds of violent protests for the fourth consecutive day, bracing for more traffic chaos as protesters have pledged to carry on with their new strategy of paralysing the city’s transport link.

Classes at kindergartens and primary and secondary schools have been suspended for the day, the first time this week, while major universities have announced they will shorten the term or replace on-campus classes with online lectures, for now, the South China Morning Post reported.

On Wednesday, there were no confrontations at Chinese University, the site of a fiery battlefield where protesters and police locked horns in a full-day clash on Tuesday.

Earlier on Tuesday, the city’s universities emerged as a new flashpoint with sustained clashes at major campuses for the first time.

Hundreds of masked protesters, many of them students, hurled back petrol bombs, rocks and bricks, some launched with catapults. After the clashes, dozens of the injured lay sprawled on the ground at a nearby sports pitch.

On Sunday, a 21-year-old who was shot by a policeman and a 57-year-old man who was set on fire after an argument with protesters remained hospitalized in “critical condition”.

According to local media reports, some public transport services were again disrupted during rush hour on Tuesday morning, and clashes between riot police and protesters were resumed on some university campuses, where officers used tear gas.

Hong Kong has been upended by five months of huge and increasingly violent rallies, but Beijing has refused to give in to most of the movement’s demands.

Tensions have soared in recent days following the death on Friday of a 22-year-old student Alex Chow, who succumbed to serious injuries sustained from a fall in the vicinity of a violent clash the weekend before.

The controversial China extradition bill was withdrawn in early September but the movement has morphed into a wider campaign for greater democracy and against alleged police brutality.