There was applause at the Montreal courthouse from supporters of people accused of smoke-bombing the local subway system.
The four suspects will remain detained for more than a week, as their bail hearings have been postponed until May 23.
As they left the courtroom in handcuffs, their friends, fans and family gave them a standing ovation. The accused looked into the crowd and smiled. Some family members blew kisses.
The four face charges that include spreading fear of terrorism — a serious crime that could carry up to five years in prison.
Three women and one man are accused of tossing smoke bombs into various subway stations last week, shutting down service and causing a frustrating morning commute for tens of thousands of Montrealers.
There were some emotional scenes at the courthouse, with friends and family of the accused hugging each other. One young girl was crying.
There was also a protest outside the courthouse in support of the accused.
Unusual scenes unfolded there, with some journalists and protesters getting involved in shoving matches.
Some protesters accused the media of being biased against their cause and they obstructed television cameras from gathering images, doing things like tossing sheets over camera lenses. That led to some angry exchanges.
It was one of several heated scenes taking place inside and around Montreal on Monday. There were also showdowns outside schools over whether classes should be allowed to reopen following legal injunctions.