It is not clear how many people are likely to show up for the so-called "straight pride parade" in Boston Saturday, but law enforcement will be out in force.

Boston Police say they are taking all steps to provide a safe environment for the event, planned from 12-4 p.m. Police say they also expect counter-demonstrations. Organizers plan to gather at Copley Square and march to City Hall Plaza, and police say security measures will make it difficult to get around in those areas.

There will be increased uniform and plainclothes officers on duty, and checkpoints with metal detectors and mandatory bag searches at the plaza. The Suffolk County sheriff's office is providing five vans to assist in the case of mass arrests. And the local FBI office says it is also prepared to assist police if necessary.

Police are urging any Back Bay visitors to leave backpacks, strollers and large luggage behind and say everything will be subject to searches. There will be no parking around Copley Square or City Hall plaza and along the parade route. Bicycles, coolers, wagons and pets will also be banned.