Republican presidential front-runner Donald Trump will be on Long Island Wednesday to host a big campaign rally.

Trump's campaign rally at Grumman Studios in Bethpage is expected to bring up to 12,000 people, including 1,000 protesters.

At a news conference Tuesday, Nassau County Police Commissioner Thomas Krumpter said that no firearms would be permitted at the event, that there would be no bags permitted into the facility and that all participants going into the rally will have to go through metal detectors.

"Violence will not be tolerated here," he said. "I'm going to make that very clear. You will be arrested if you engage in any type of violence, and we will be equipped to handle any type of violent behavior, whether it's within the internal area of the rally or in the free speech area or the area surrounding the facility."

Police said there will two road closures beginning at 2 p.m. -- one at Grumman Road east from South Oyster Bay Road to the end and the other at South Oyster Bay Road between Grumman Road and South Broadway. The closures are expected to last until 10 p.m.

Krumpter said the security measures are expected to cost about $400,000 -- none of which will be reimbursed by Trump's campaign.