Lawyers for two parents and a 17-year-old boy in Thompson, Man., filed a constitutional challenge Monday against the city for a curfew they say discriminates against young people by banning them from city streets at night.

The Public Interest Law Centre, which is a service of Legal Aid Manitoba, filed a statement of claim Monday in Court of Queen's Bench on behalf of Lynn Sauve, her 17-year-old son and another mother. It claims that the curfew bylaw, which city council adopted on July 18, 2005 in an effort to curb vandalism, violates the Charter of Rights and Freedoms.

The curfew prohibits youth from being alone or unaccompanied by guardians while out in public after certain hours: 10 p.m. for children under 12, 11 p.m. for those 12 to 15 and midnight for 16- and 17-year-olds. The curfew is lifted at 7 a.m. the following morning.

Children and youth can be fined up to $500 for not obeying the curfew. Their parents or guardians can also be fined for not making sure their children follow the curfew.

Sauve said Monday that the bylaw discriminates against all children and teens, including the ones she sees at the Boys and Girls Club program she runs in Thompson.

"If our students are leaving here in the evening, they're going to get picked up. For what? Not drinking and trying to stay out of trouble and utilizing the computers and watching TVs that they don't have at home?" Sauve said.

"It just frustrated me because I've never given my own 17- and 19-year-old a curfew ever."

Mayor Tim Johnston said Monday that no child has been charged under the bylaw to date. Rather, he said, police use the bylaw to warn kids seen out late to get home.

The city has not yet filed a statement of defence. Johnston had no comment on the lawsuit itself, as the city seeks legal advice.

Johnston's predecessor, Bill Comaskey, told CBC News in September that he did not support the curfew, but his council passed it as a way to curb vandalism and crime by local youth.

Curfew violates several rights: lawyers

Winnipeg lawyer Myfanwy Bowman, who is helping Sauve with several arguments, said Monday their challenge of the curfew will address part of the charter that deals with children's right to equality.

Her Thompson counterpart, Ron Dearman, said the curfew violates young people's freedom of association and right to be free from arbitrary detention.

"This bylaw would allow a police officer to come and take a child off the street and detain him and then return him to his parents," Dearman said.

"It affects the liberty and rights of each child to be subject to such arbitrary detention."

Dearman added that the curfew is unfair because it penalizes all youth, even those who have done nothing wrong.

"In Manitoba we have child welfare laws that the police and the child welfare authorities have already to enforce," he said.

"But to make it a blanket [law] to pick up any and every child who may be on the street after a certain hour goes way beyond the powers that the city has been given under federal and provincial legislation.

Dearman and Bowman had raised the possibility of a legal challenge with the city in May 2006. They had asked the city to amend or rescind the bylaw, but the city never gave them a response.