Updated

A judge gave the green light Thursday to a lawsuit against police officers in the arrests of 700 Occupy Wall Street protesters last year on the Brooklyn Bridge, but he dismissed the city and its top officials from liability.

U.S. District Judge Jed Rakoff in Manhattan said in a written ruling that the marchers had adequately backed up their claims at this stage of the litigation that they were not properly warned by officers that they would be arrested on the bridge Oct. 1.

But the judge tossed out as defendants the city, Mayor Michael Bloomberg and police Commissioner Raymond Kelly, rejecting the argument that the city and its top officials had a policy of making false arrests designed to discourage protesting.

City lawyer Arthur Larkin said the city was pleased that the judge found neither the mayor nor the police commissioner was liable. He said the city was considering its legal options, including appeal, regarding the remainder of the decision.

The judge began his decision by citing the contributions of people such as Thomas Paine and Martin Luther King Jr., saying "what a huge debt this nation owes to its 'troublemakers.'"

"They have forced us to focus on problems we would prefer to downplay or ignore," he said. "Yet, it is often only with hindsight that we can distinguish those troublemakers who brought us to our senses from those who were simply — troublemakers. Prudence, and respect for the constitutional rights to free speech and free association, therefore dictate that the legal system cut all non-violent protesters a fair amount of slack."

The ruling came in one of several lawsuits that resulted from the protest in which protesters were surrounded by officers in the middle of the bridge and arrested.

The protesters were demonstrating against financial inequality. Their lawsuit seeks a judgment declaring their arrests were unconstitutional and unspecified damages.

Police said the protesters were arrested and given disorderly conduct summonses for spilling into a roadway despite warnings.

The judge, in his ruling, said the plaintiffs had made an adequate showing that police failed to give fair warning to the majority of protesters that they would be arrested if they marched in traffic lanes on the bridge. He said the protesters were further confused when police officers walked into the lanes themselves and stopped traffic, making it seem as if it was all right to be there.

The judge said the videos offered by both sides show that the police officers "exercised some degree of control over the marchers, defining their route and directing them, at times, to follow certain rules."

He said the use of one bull horn to warn demonstrators where to go was clearly inadequate because "no reasonable officer could imagine, in these circumstances, that this warning was heard by more than a small fraction of the gathered multitude."

"Indeed, the plaintiffs' video shows what should have been obvious to any reasonable officer, namely, that the surrounding clamor interfered with the ability of demonstrators as few as 15 feet away from the bull horn to understand the officer's instructions," the judge added.