Dozens of people held a vigil in Montreal Thursday in support of two Canadian women arrested earlier this week in connection with a firebombing at a Mexico City government office.

The group gathered outside the front entrance of a downtown building that houses the Mexican Consulate.

Mexican authorities say they arrested Canadians Amelie Pelletier and Fallon Rouiller Poisson after Molotov cocktails were lobbed at a federal office in the Mexican capital.

A Mexico City prosecutor has told local media that police allege one of the Canadians was seen discarding a backpack that contained a number of homemade explosive devices.

Organizers of the Montreal vigil declined to address media, but a statement was read aloud to the group by well-known activist Jaggi Singh.

The statement says the Mexican justice system is repressive and authoritarian and considers detainees guilty until proven innocent.