New York City notified a federal appeals court Friday that it will challenge a judge's ruling limiting when police can search demonstrators at events such as the Republican National Convention (search).

The city government said it was wrong "at this dangerous time" to impose judicial oversight as the city decides how to protect the public.

Still, though, the city did not seek immediate action by the 2nd U.S. Circuit Court of Appeals (search) in Manhattan, meaning that the July 19 order by Judge Robert W. Sweet will remain in place during the convention, scheduled for Aug. 30-Sept. 2.

Sweet said the city had not proven that the "general invocation of terrorist threats" was sufficient to justify the invasion of personal privacy without showing how searches would reduce the threats.

In a release, the city said it "strongly disagrees" with Sweet's order. It added, however, that the ruling has little practical effect, since the judge gave police permission to search bags in certain instances and the police department had already changed other procedures to promote the smoother flow of people from block to block.

City lawyer Michael A. Cardozo (search) said the city's policies regarding blanket searches of bags at demonstrations was constitutional.

"Particularly at this dangerous time, it is wrong to subject the NYPD to contempt proceedings when it must make difficult decisions about how to secure public safety," Cardozo said.

He said the city interpreted the judge's order to mean it can conduct blanket searches "when there is a threat, even though it may not be specific as to time and place."

Cardozo said the order gave the police "the necessary flexibility to take steps, where necessary, to conduct blanket bag searches."

Donna Lieberman, executive director of the New York Civil Liberties Union, said the judge's ruling "strikes the proper balance between security and free speech and we'll defend it on appeal."

"With regard to the searches, the devil will be in the details. The New York Civil Liberties Union will monitor very closely how the city deals with the situation," she said.

She also suggested that the city might be interpreting the judge's language about blanket searches too broadly.

Lieberman said the judge required "a showing that the searches will in fact respond to any security threat that exists. It's far from an invitation to blanket searches."

Besides his ruling on bag searches, the judge also said police must provide reasonable access to streets where metal barricades are used to control crowds, rather than refusing access to blocks once they become full, even after space opens up as people leave.

The ruling came in a case brought on behalf of several people who complained about police actions during a February 2003 anti-war protest prior to the U.S. invasion of Iraq.

Police cited continuing terrorism threats as the chief reason why security must be tight during the convention.