A man and three women in their early 20s have been charged with committing a terrorism-related prank following smoke-bomb attacks that crippled the Montreal subway system Thursday.

The suspects, François-Vivier Gagnon, Geneviève Vaillancourt, Vanessa L'Écuyer and Roxanne Bélisle, turned themselves in to authorities Friday at an undisclosed police station, accompanied by lawyers.

They appeared in court via video conference Saturday to face charges of inciting fear of terrorism, which carries a maximum sentence of five years in prison.

They were also charged with conspiracy and mischief of over $5,000, while Gagnon was charged with possession of a prohibited weapon (police allege he had a knife).

The morning rush-hour attacks prompted a mass evacuation of the underground network, and subway service was paralyzed for more than three hours, leaving hundreds of thousands of commuters stranded.

They're wanted in connection with the smoke bomb that went off at the Lionel-Groulx Metro station. Two other smoke devices were detonated at the Préfontaine and Jean-Talon stations.

The suspects included some people identified via eyewitness pictures taken by commuters during the smoke bomb incidents.

Their names were widely circulated in Montreal media outlets Friday, but police Sgt. Ian Lafrenière wouldn't confirm the suspects' identities.

Authorities are still seeking suspects linked to the other two smoke bombs incidents.