New York City has reached the outlines of a settlement with Muslims who challenged police surveillance as an unconstitutional intrusion on their religious rights.

City lawyers say in a letter filed Friday there’s a “settlement in principle” in a 2013 lawsuit filed by mosques and others but some details remain unresolved. The letter says the terms can’t be disclosed, citing a confidentiality order.

The city Law Department, the American Civil Liberties Union and the New York Civil Liberties Union declined to comment Monday.

The ACLU and the NYCLU are among the plaintiffs’ lawyers. They say the New York Police Department surveillance stigmatized law-abiding Muslims.

The city’s legal department has called the intelligence-gathering an appropriate and legal anti-terrorism tactic.

The lawsuit came after reports by The Associated Press disclosed details of the spying program.

(AP)