Starting Thursday, Disneyland will use metal detectors to randomly screen visitors as part of a new set of rules aimed at bolstering security at the Anaheim theme park, officials said.

Guests will first pass through the park's long-standing bag-check area, then proceed to the park entrance, where some will be randomly selected to walk through a metal detector, Disneyland spokeswoman Suzi Brown said.

Two other rules will also take effect: guests 14 and older will not be allowed to wear costumes or masks, and toy guns - including toy blasters and squirt guns - will be banned and stop being sold at the park.

Visitors can also expect to see more uniformed Anaheim police officers outside the resort, Brown said. Bomb-sniffing dogs have been used for the past few weeks.

Brown said the changes were made "given the current state of heightened awareness," and "not based on any single incident or event."

"We continually review our comprehensive approach to security and are implementing additional security measures, as appropriate," she said.

In July, a 44-year-old San Francisco man was arrested on the walkway between Disneyland and California Adventure on suspicion of carrying a loaded handgun. Police said he walked through a security checkpoint without employees noticing the pistol. And in April, a man snuck a gun into Universal Studios Hollywood and fatally shot himself.

Other Southern California theme parks have released statements on what they're doing to beef up security this holiday season:

Knott's Berry Farm : "Multiple layers of protection" are in place, including metal detectors, bag checks and other features that are not visible to park guests.

: "Multiple layers of protection" are in place, including metal detectors, bag checks and other features that are not visible to park guests. Legoland : "Additional security measures" are in place and the park said it is working closely with law enforcement agencies.

: "Additional security measures" are in place and the park said it is working closely with law enforcement agencies. SeaWorld : The park confirmed it has strengthened security, but did not release details "in order to maintain their effectiveness."

: The park confirmed it has strengthened security, but did not release details "in order to maintain their effectiveness." Six Flags Magic Mountain : Security measures include metal detectors, bag checks, off-duty officers and "seen and unseen security."

: Security measures include metal detectors, bag checks, off-duty officers and "seen and unseen security." Universal Studios Hollywood: The park has begun testing metal detectors that have typically been used for special events, such as Halloween Horror Nights.

In Orlando, Florida, the Walt Disney World, Universal and SeaWorld theme parks have also begun installing metal detectors.