PITTSBURGH — City police wrongly arrested 25 people — and used unnecessary force against some of them — to "punish" them for participating in or being near an anti-police brutality protest after the Group of 20 summit ended in the city last year, the American Civil Liberties Union said in a lawsuit.

The ACLU filed a 42-page federal lawsuit today that alleges police created most of the problems themselves by surrounding about 100 people with officers in riot gear then ordering them to disperse. Many who tried to leave couldn't and five people who were not even at the protest were arrested blocks away, the ACLU contends.

The ACLU announced the lawsuit at a plaza near the University of Pittsburgh campus where the protest was staged on Sept. 25, 2009.

Pittsburgh police spokeswoman Diane Richard relayed a copy of the lawsuit to the city's law department, which did not immediately comment on it.