PITTSBURGH — The American Civil Liberties Union sued Pittsburgh, the Secret Service and a state agency on Friday, claiming they are violating the civil rights of people seeking to protest the Group of 20 global economic summit.

Protesters have claimed the city is stalling in issuing permits they need to demonstrate during the summit on Sept. 24 and Sept. 25. On Friday, protesters said they had waited too long and had no choice but to get the court to force the agencies to issue the permits.

The ACLU's lawsuit was filed on behalf of six groups that want to be allowed to hold a demonstration less than a mile from the summit site on Sept. 25.

The lawsuit says Pittsburgh and the Secret Service have "unduly restricted or failed to recognize" the right of "peace, social justice and environmental justice organizations" to "peaceably demonstrate in traditional public forums."

Thousands of protesters often accompany global summits such as the G-20, opposing policies they feel harm everything from the environment to the poor.

Nearly two dozen world leaders are attending the summit as part of a global effort to deal with the economic crisis.