In what organizers said was both an educational exercise and an effort to keep up momentum, protesters marched through Center City Philadelphia on Saturday, calling for the elimination of ICE, the U.S. Immigration and Customs Enforcement agency, and practices considered unfair to immigrants in a place that has declared itself a "sanctuary city."

The demonstration began at the Liberty Bell and included a circuitous trek to City Hall with brief stops at police headquarters and ICE offices.

Leaders said the march was intended as a celebration of Mayor Kenney's decision to allow a controversial city contract with ICE to expire. The contract gave ICE access to a key law enforcement database known as PARS — the  Preliminary Arraignment Reporting System — which critics said had been used to harass undocumented but otherwise law-abiding immigrants in Philadelphia. The contract terminates on Aug. 31.

Saturday's protest, which attracted about 200 participants, had been scheduled before Kenney's PARS decision and remains important "because of the political education aspect," said Timour Kamaran, 25, of West Philadelphia, one of the organizers.

"People on the periphery of the movement might not know the specifics of what we're asking … so we're providing ideological clarity," he said.

Said another organizer, Sarah Giskin, 24, of Brewerytown: "If this is a sanctuary city, ICE shouldn't be welcome here at all."

A planned counterdemonstration in support of ICE failed to materialize on Independence Mall.

Walter Smolarek, a radio producer originally from Pittsburgh, said the anti-ICE demonstration would show activists "are committed to keeping the struggle going."

"The PARS victory was energizing because it showed that public pressure is able to make the politicians do the right thing," Smolarek said. "We think the purpose of ICE is to sow terror in communities."

Around noon, the protesters' route took them by the ICE offices at Eighth and Cherry Streets, where demonstrators stopped briefly and chanted: "When immigrant families are under attack, what do we do? Stand up, fight back." Police patiently looked on. No ICE employees appeared to be on the premises.

Marchers — including veterans of 1960s peace demonstrations and mothers holding young children — then resumed their hike, turning west onto Market Street in a peaceful walk to cadences of rhythmic slogans. A phalanx of bicycle police, dismounted and pushing their bikes, formed a southern edge of the march.

At City Hall, speakers from a number of social-justice groups demanded that the feds dissolve ICE, that Gov. Wolf order the closing of  the Berks family detention facility, and that Philadelphia's stop-and-frisk policing policy come to an end.

Rabbi Linda Holtzman, addressing the crowd near the memorial to civil rights activist Octavius Catto, praised Mayor Kenney for "separating the Philadelphia police from ICE," but said that any institution that separates parents from their children must be dissolved  "in the name of justice."

"ICE must go," Holtzman said.

What is formally known as the Berks County Residential Center is the oldest and smallest of the three detention facilities in the U.S. A low-security lockup in Leesport, about 75 miles northwest of Philadelphia, the 96-bed facility holds parents and their children who came into the country seeking asylum without papers.

On Tuesday, four protesters were arrested during a contentious Occupy ICE demonstration at Broad and Arch Streets in Center City, where an encampment had been set up after the group was evicted last weekend from the east side of City Hall. City officials said that area was about to become a construction zone for a long-planned project.

Earlier in July, Philadelphia police raided and destroyed the Occupy ICE encampment that set up outside the ICE office at Eighth and Cherry.

Carol Mickey, 76, of Gulph Mills, walked the entire length of the march. A restaurateur and attorney, who participated in protests nearly 50 years ago ("I had younger knees then," she said), Mickey said she supported the cause, even if she disagreed with the organizers' specific demands.

"If they close down Berks, they'll just move those people elsewhere," Mickey said. "And you can't abolish ICE. It serves a purpose. But it's like anything good that's turned evil. It just needs to be reformed."