(Reuters) - An Alabama city appears to be the first in the country to specify criminal penalties for violators of an ordinance requiring people to use bathrooms that match the gender on their birth certificates, civil rights groups said on Wednesday.

The law passed on Tuesday by the city council in Oxford, located about 60 miles east of Birmingham, carries a possible punishment of a $500 fine or six months in jail.

The measure raises the stakes in the U.S. bathroom wars that have caused fierce debate among state lawmakers, school officials and Republican presidential candidates. It goes further than a law enacted last month in North Carolina - which has been boycotted by businesses, entertainers and government workers - since it became the first state to bar transgender people from using bathrooms that correspond with their gender identity.

North Carolina’s law applies to restrooms and locker rooms in government-owned facilities and schools.

The Oxford ordinance also includes bathrooms in private businesses and explicitly makes violating the provision a crime, the Human Rights Campaign said.

“This is a very concerning expansion of the ways in which trans people are going to be and have been policed,” said Chase Strangio, a staff attorney with the American Civil Liberties Union’s LGBT Project. “It’s essentially just criminalizing trans existence.”

Steven Waits, president of the Oxford City Council, said the measure was a response to complaints from residents after retailer Target last week said transgender people and customers could use store bathrooms that matched the gender with which they identify, the Anniston Star reported.

Waits said the council adopted the law “not out of concerns for the 0.3 percent of the population who identify as transgender,” but “to protect our women and children,” according to the newspaper.

Waits did not reply to a request for comment from Reuters.

Strangio said the law raises constitutional questions and the ACLU was considering taking legal action to block it. The group already has sued North Carolina over its law.