Pure, potent methamphetamine is appearing on the streets of Tucson, courtesy of Mexican drug-trafficking organizations, the Arizona Daily Star reports.

Domestic production of meth was drastically reduced in 2005, when legislation was passed that restricted the availability of meth’s main ingredient, pseudoephedrine, found in cold medicines. Now, Mexican drug manufacturing operations have refined their techniques, making the drug more potent and worrisome to law enforcement officials.

The article notes Tucson is a major distribution hub of this new meth. At least 450 pounds of meth was seized by the Border Patrol’s Tucson Sector this year through May. Local police estimate they may be catching only 10 percent of the drug that is moving through Pima County, where Tucson is located.

Authorities say it is difficult to break up the new meth rings because they only need a small stash and a cellphone to operate. They note a high from meth can last for hours, causing paranoia and hallucinations. Use of the drug sometimes can lead to violent behavior.