A federal judge on Wednesday toured a designated protest area encased with concrete barriers, steel fencing and razor wire, after activists planning to demonstrate during next week's Democratic National Convention charged Boston police with infringing on their free speech and making them unsafe.

Attorneys for the coalition led by the Black Tea Society, which describes itself as antiauthoritarian, argued in a complaint filed in U.S. District Court that the area set aside by the city is unsafe and too heavily barricaded to allow for free speech.

In another case, the judge, Douglas P. Woodlock, heard arguments from Act Now to Stop War and End Racism (ANSWER), which was denied a permit to parade about 2,000 people from Boston Common to the FleetCenter on Sunday, the day before the convention is to begin. Woodlock did not indicate when he would rule on this case but scheduled another hearing for Thursday.

Federal officials have designated the convention a special security event and have warned that terrorists may be plotting to disrupt the election season.

Protesters say police are using that pretext to deny them basic rights.

"The overall message is that there is an incredible overuse of force that implies you are not welcome to come to Boston to be heard," said Carol Rose, executive director of the American Civil Liberties Union of Massachusetts, which along with the National Lawyers Guild is arguing both cases.

A lawyer for the Boston Police Department, Mary Jo Harris, called the restrictions "reasonable."

Several dozen protest groups plan activities during next week's convention, including a Sunday afternoon antiwar rally on Boston Common organized by ANSWER, which refers to Republicans and Democrats as "the twin parties of the war machine." The Black Tea Society plans marches against police brutality on Monday and U.S. oil policy on Thursday.

Other groups include several families of those who died in the Sept. 11, 2001, attacks. They will be pushing a 1,400-pound stone in honor of "unknown civilians killed in war" from Boston to New York, where Republicans will gather next month.

Organizers of the largest anti-war demonstration scheduled for the Republican National Convention announced Wednesday that they will accept New York's offer to use the West Side Highway.

United for Peace and Justice, the lead organizing group for an event expected to draw 250,000 on the eve of the convention, had asked to hold the demonstration in Central Park, but the city refused and offered the highway.

"At this point, to keep fighting and not have an agreed-upon location for the rally would undermine our ability to mobilize people," said Leslie Cagan, the group's national coordinator.

The demonstration area in Boston is about one block from the FleetCenter, directly under an unused elevated highway. It was moved from a site farther away after activists complained, and is near a bus depot to be used by delegates all week.

The suit filed Wednesday charges that opaque fences will prevent protesters from communicating with delegates, and that the low ceiling and two narrow exits make it dangerous to demonstrators.

The dispute over the parade planned for Sunday hinges on whether demonstrators can walk down Causeway Street, which leads past the side of the FleetCenter.

"It means something to be able to say we marched to the doorstep of the [convention]," said Dustin Langley, a spokesman for ANSWER. "We'll fight it in the courts or we'll fight it in the streets."

Special correspondent Michelle Garcia in New York and researcher Lucy Shackelford in Washington contributed to this report.