South Bay police agencies are ramping up for possible trouble this weekend as an organization that many consider a hate group prepares for a demonstration in Santa Clara, and a large counter-protest is expected.

Act for America has been described as the largest anti-Muslim organization in the country, a description its leaders dispute. The nation's largest Muslim-American group, CAIR, is preparing to lead the counter-protest consisting of about 75 Bay Area community groups.

The groups are expected to converge at Stevens Creek and Winchester boulevards, an intersection that borders San Jose and Santa Clara. It's a strategic move because when one city's police show up, the protesters move across the street into another jurisdiction.

But Saturday will be different, as both San Jose and Santa Clara police plan to be on hand with extra staffing.

The Act for America march is one of several across the nation taking place Saturday, according to its website. Organizers have emphatically denied being an anti-Muslim hate group, as it has been designated by the Southern Poverty Law Center. Officials say its members are a mix of race, faith and political affiliations, and their march is actually a protest against "sharia law," a part of Muslim law that they say promotes abuse toward women.

The counter-protesting groups, however, say they're not fooled and have organized a vigil across the street.

"There has not exactly been an outbreak of sharia law in the area," said Rev. Diana c. Gibson of the Multifaith Voice for Peace and Justice. "The reason they chose Santa Clara is pretty clear to me because we have a strong, rich, vibrant and respected Muslim community here."

About 75 other groups signed on to co-sponsor the counter-protest. CAIR says it's important the event isn't perceived simply as a Muslims vs. anti-Muslims encounter.

"Act for America is a vitriolic hate group that wants to deprive Muslims and others of their human and civil rights," said Zahra Billoo, CAIR's Bay Area director. "Our partners, rightfully so, didn't think it was OK for these hate mongers to come into our city and not have their message challenged."

Act for America organizers did not return calls requesting comment about the Saturday protest.

Santa Clara and San Jose police met to discuss strategy, NBC Bay Area learned, and both agencies plan to beef up staffing and coordinate any enforcement action, if needed.