Arms smuggling is a growing problem in Latin America and the United States is the source of many of the weapons that are being bought and sold illegally in the underground market. That issue was the focus of a meeting Monday of hemispheric police and public security officials in Rio de Janeiro.

There are no reliable statistics on the extent of illegal arms trafficking in Latin America, but authorities believe it is on the rise.

John Malone, who is the Deputy Director of the U.S. Bureau of Alcohol, Tobacco, and Firearms, says many of the weapons sold illegally in Latin America come from the United States. He says last year his bureau traced some 9,500 U.S.-made guns that ended up in South America illegally. Another 5,000 guns were traced to Mexico alone.

Mr. Malone says automatic and semi-automatic weapons are becoming the top choice for smugglers and their customers. "We've had an inordinate amount of AK-47 [assault] type of rifles," he said. "We've had a lot of handguns, we've had a lot nine millimeters. In years past there were a lot of 38 caliber [revolvers] recovered, because that was the type of weapon that had been manufactured for decades. They're still being manufactured, but the weapons of choice recently have been the nine-millimeter, semi-automatic type of handguns."

These weapons end up in the hands of criminals, especially drug traffickers. Street gangs in the big cities of Latin America also receive many of these smuggled, American-made guns. Mr. Malone says there is also evidence the Colombian guerrilla group, FARC, has been buying U.S. made guns on the black market.

Mr. Malone says the Bureau of Alcohol, Tobacco and Firearms is trying to stop arms smuggling to Latin America at the source. "We've got more agency personnel looking at it," he said. "We've enhanced our crime gun analysis branch, so we can determine firearm trafficking patterns here in South and Central America. What we want to do is find out where the guns are coming from in the United States and stop the flow there, rather than stop the flow on this end."

Bureau investigations show many of the smuggled weapons originate from the U.S. states of California, Florida, and Texas.

Mr. Malone is among several hundred delegates attending a two-day conference in Rio de Janeiro on Public Security in South America. The meeting, sponsored by the International Association of Police Chiefs, has brought to together top security and police officials from the Americas to discuss issues such as arms and drugs smuggling, money laundering, and corruption.