Scuba divers

Washington (CNN) -- Scuba divers, take note: Please leave your spear guns at home, or place them in your checked luggage. But do not try to bring them on a plane.

A passenger at a New York-area airport learned that lesson the hard way last week when a TSA screener discovered a 21-inch spear gun and a utility knife in a carry-on bag.

The passenger arrived at Newark Liberty International Airport ticketed to fly to Antigua. After his weapons were detected, the TSA contacted local law enforcement, who questioned the passenger, said TSA spokesman Kawika Riley. The passenger claimed to be unaware that the weapons were prohibited, the TSA said.

There was no impact on airport operations.

"Just to be clear, passengers should not attempt to bring a spear gun as a carry-on item. The same rule holds for utility knifes," Riley said.

Spear guns are specifically prohibited in carry-on bags. On the TSA web site, they are listed under prohibited sports goods, which include baseball bats, ski poles, and bows and arrows.

The TSA said most passengers who carry prohibited items do so without ill intent, but said officers have a responsibility to prevent weapons from getting through the checkpoint.

In the week since the spear gun was found, the TSA says it has found 24 loaded and four unloaded firearms in carry-on baggage.