Guns on the Move These new covert guns were first discovered in October when Dutch police stumbled on a cache during a drug raid in Amsterdam. In another recent incident a Croatian gun dealer was caught attempting to smuggle a shipment through Slovenia into Western Europe. Police say both shipments are believed to have originated in Yugoslavia. Interpol sent out a warning to law enforcement agencies around the world. European border police and customs officers are at a heightened state of alert at all ports, airports and border crossings.  Realistic Appearance If you didnt know they were guns, you wouldnt suspect anything, said Ari Zandbergen, spokesman for the Amsterdam police. Only when you have one in your hand do you realize that they are heavier, says Birgit Heib of the German Federal Criminal Investigation Agency. The guns are loaded by twisting the phone in half. The .22-caliber rounds fit into the top of the phone under the screen. The lower half, under the keyboard, holds the firing pins. The bullets fire through the antenna by pressing the keypad from numbers five to eight. Amsterdam police says they are very sophisticated machines constructed inside gutted cell phones which do not light up or operate as real phones. These are very difficult to make. We believe experts are involved, says Zandbergen.  America on Alert U.S. authorities, including the FBI, ATF, Federal Aviation Administration and the U.S. Customs Service Authority have been supplied detailed information and pictures of these new weapons. Theyve been given a heads up, said Jim Crandall, ATF spokesman. To date no phone guns have been discovered either in the United States or in the process of being smuggled in, authorities say. But they know its only a matter of time. FAA spokeswoman Rebecca Trexler said airport security officers had been trained to deal with this new threat. We dont want to tell the bad guys exactly what were looking for, she says, We are trying to stay one step ahead.  Will Affect Travelers Airport authorities across Europe are implementing systems to X-ray all cell phones, those procedures will likely be followed by airports around the world. This is just one more item that we need to pay special attention to because nowadays, of course just about every passenger carries a mobile phone, says the spokesman for Frankfurt airport security. Customs officials in the U.S. say their safety procedure has normally been to require travelers to turn their phones on, however that may no longer be enough. Cell phone users will have to be made aware that reaching for their phones in some circumstances could be misinterpreted as a threat by authorities.  ABCNEWS Christel Kucharz in Bonn and Andrew Chang in New York contributed to this report.
- At first sight it looks like a regular cell phone - same size, same shape, same overall appearance.