MONTREAL -- The mother of a Canadian woman arrested in connection with a Mexico City firebombing says she's deeply concerned about her daughter's well-being.

Mexican authorities detained Canadians Amelie Pelletier and Fallon Rouiller Poisson earlier this week following a Molotov cocktail attack Monday against a government office in the capital.

Poisson's mother, Line Rouiller, told The Canadian Press on Wednesday she was stunned to hear about her daughter's arrest.

"I don't feel good at all ... I don't know what's going on," said Rouiller, who was also unsure of the severity of the accusations against her 20-year-old daughter from Montreal.

"If (the alleged attack) is against government property, she's in big trouble."

Veronica Perez of Mexico City's attorney general's office said Wednesday that Poisson and Pelletier were nabbed after Molotov cocktails were tossed at a building that houses the Department of Communications and Transportation.

Mexican officials have said no injuries were reported in the attack, which damaged several vehicles outside a nearby car dealership. The motive was not immediately clear.

A Mexico City prosecutor told local media that a Mexican national was arrested along with the two Canadian women, who were later transferred into the custody of the Central Investigation Agency. He said police have alleged that one of the Canadians was seen discarding a backpack that contained a number of homemade explosive devices.

Police in Mexico could not be reached Wednesday to comment on the case and whether the women had been formally charged.

Rouiller said she's been in contact with the Canadian Embassy in Mexico and was waiting for information about Poisson's situation. She added that her daughter was mistakenly identified by Mexican authorities as Fallon Poisson Rouiller.

Canada's Foreign Affairs Department has confirmed it is aware that two Canadian citizens were detained in Mexico.

"Canadian officials are in contact with local authorities to gather additional information and consular services are being provided," department spokesman Mathieu Roy said Tuesday.

Following her arrest, Poisson phoned her grandmother in Canada. Rouiller said she told her grandmother she had been roughed up following her arrest.

"They hurt her a bit," said Rouiller, who added she had never heard of Pelletier. "I don't think it's a good place to get arrested."

Rouiller said Poisson participated in Quebec's massive 2012 student demonstrations, but insisted her daughter would never take part in such destruction.

"I know my daughter," Rouiller said in a phone interview from her home in suburban Montreal, an area where Poisson grew up.

"She's the adventurous type, but she's more sporty and likely to go to a protest than to destroy someone else's property."

A former colleague of Poisson's described her Wednesday as someone with strong political beliefs.

"She was extremely dynamic in everything she did," said Etienne Philippart, the co-ordinator of the students' association at Poisson's former junior college, CEGEP du Vieux-Montreal.

"When she's implicated in something, she goes right to the limit of her convictions."

Philippart, who employed Poisson at the association's office from the start of the 2012 fall semester until her graduation last June, said she was very involved in political life at the college, which was recognized as one of the most militant schools during Quebec's student crisis.

The student movement, which erupted over tuition-fee hikes and became known as the Maple Spring, made international headlines with its huge, nightly marches on the streets of Montreal over a period of several months.

"She participated very actively in the Maple Spring," said Philippart, who added that Poisson was in favour of some of the more-active forms of protest witnessed during the crisis, such as blocking bridges.

"She had an ideology, she believed it and she had strong, precise convictions."

As for Pelletier, Philippart said he had never before heard of her, either.

One fellow Vieux-Montreal student, also a former co-worker of Poisson's, described her as a "militant anarchist" involved in radical organizations such as anti-capitalist groups.

"She was quite an emotional person, very enraged by the system," said the student, who spoke on condition of anonymity out of concern of facing harassment for speaking to the media about her.

"She was very, very anarchistic."

The student called her a decent worker and added they never had any personal conflicts when they shared shifts at their off-campus job.

As an employee, Philippart recalled how Poisson was kind to him when his wife fell ill, saying she was quick to volunteer to fill in for him when he had to attend doctor's appointments.

He said Poisson earned good grades and graduated from the school's Optimonde social-sciences program, which included Spanish lessons and an internship in Ecuador.

Poisson's mother, meanwhile, said her daughter travelled to California in September and has been in Mexico since November.

"My daughter isn't like this," Rouiller said, referring to the allegations.

"I'm very surprised."