"There will be metal-detection screening, similar to what you experience at airport security," said deputy chief John Viola of the Haverford Township Police Department, who is overseeing the law-enforcement operations. "This screening process is designed to prevent spectators from bringing prohibited items onto the championship grounds. Our goal is to assure that everyone has a safe and an enjoyable experience at the U.S. Open."

Among the items prohibited on the course are cell phones, PDAs and tablets, cameras, signs and bags larger than 8 inches square. Chairs, step stools and stepladders also are prohibited.

"We encourage all spectators to review the list of prohibited items and secure those items in a safe place or leave them at home," Viola said.