Mexican drug cartels are suspected of smuggling terrorists and explosives across the border into the United States, according to a report by the U.S. Army’s Asymmetrical Warfare Group (awg). The 350-strong “special mission unit” that works to “identify critical threats and enemy and friendly vulnerabilities through global firsthand observations,” according to the Army, compiled a report on a secret intelligence mission conducted along the southern U.S. border during February and March, releasing a “cleansed” version to civilian law enforcement, which was viewed by Newsmax.

The report states that drug cartels have “exceptional surveillance and countersurveillance capabilities, robust technical communications capabilities as well as effective marking and signaling techniques to facilitate smuggling of illegal personnel and illicit cargo into the United States.”

It states that some of the aliens smuggled into America are suspected of being Middle Eastern terrorists.

The awg found that smugglers have hidden containers within large liquid haul tanks. The report warned that terrorists could use this technique “to deliver explosives onto U.S. bases, compounds or through ports of entry.” The report added: “The carrier could vary from a small automobile gas tank to a large seafaring oil tanker. The ability to detect this transport method exploits the current tactics that border authorities use to identify false compartment unless X-ray machines are available.”

Cartels also operate 50 to 80 “semi-submersibles,” hard-to-detect boats that float mostly underwater. They are “capable of moving large amounts of narcotics virtually undetected,” according to the report.

These boats are 33 to 60 feet long, can travel roughly 2,000 miles, and are virtually invisible to sonar and radar.

U.S. officials are worried that these semi-submersibles could be used to carry a lot more than drugs. “If drug cartels can ship up to 10 tons of cocaine in a semi-submersible, they can clearly ship or rent space to a terrorist organization for a weapon of mass destruction or a high-profile terrorist,” said Navy Adm. James Stavridis in August last year.

Drug cartels are becoming increasingly active in the U.S. A 2008 report found that cartel distribution networks linked 203 cities across the country. With the cartels comes the drug-related violence and torture. But they could also be bringing into the country other deadly cargo: terrorism, possibly even nuclear terrorism. America’s porous border is a huge security threat.