MONTREAL—Smoke bombs were set off at multiple points in Montreal’s subway system today, cutting off service and creating a nightmarish morning commute.
The incident occurred near the peak of the rush hour.

There have been other interruptions to subway service in recent weeks as the city deals with unwieldy protests, but this one was notable.
There were reports of smoke-filled stations at key transfer points—crippling the entire network.
Quebec Premier Jean Charest swiftly condemned the attack, saying he hopes the guilty parties are found.
“It’s inexplicable,” Charest told reporters in Gatineau, Que. earlier today.
“There’s no reason to commit acts of intimidation and violence,” he stressed.
“There’s no excuse for this—none.”
An attempt to restart the system quickly failed, with another smoke attack reported, prompting authorities to declare yet another shutdown.
Service began returning on a gradual basis after 9:30 a.m.
The trickle-down effect was felt in the city’s streets, with long lineups at bus stops and increased traffic under a heavy drizzle.
There were reports on social media of some incidents, like ambulances struggling to get through traffic.
Locals vented their rage.
One listener wrote to local radio station CJAD to say Premier Jean Charest should withdraw whatever offer he has made to students, and demand that the army be called in.
Other commenters on news websites likened it to domestic terrorism.
Police, however, have not pointed the blame at anyone yet. They repeatedly have said in recent weeks that some radical groups have been taking advantage of students’ anti-tuition battle to create their own damage.
There also were reports of civic-mindedness today, with people offering rides and with a temporary increase in BIXI public-bicycle service.