Three Charleston area merchants have been indicted on federal drug charges as part of a nationwide crackdown on synthetic marijuana, a designer drug linked to bizarre behavior and health problems.

Federal grand juries in Charleston returned indictments this month against Vedit Patel, owner of the Tobacco Co. in North Charleston, and Khalid Ibrahim and Firas Abuamsheh, owners of Kelly’s Quick Stop in North Charleston and Bacons Bridge Road Quick Stop in Summerville, authorities said.

All three face drug-conspiracy and money-laundering charges.

U.S. Attorney for South Carolina Bill Nettles said the indictments are part of an ongoing investigation aimed at shutting down sales of the potent and potentially dangerous fake pot, also known as K2 and Spice.

Federal and state authorities have moved in recent years to close legal loopholes that allowed sales of the faux pot — herbal mixtures sprayed with a stew of chemicals that mimic marijuana’s main active ingredient, THC — to creep into corner stores and other outlets.

The pouches often are marketed as incense or potpourri, but sell for $20 to $80 a pop, said Assistant U.S. Attorney Peter Phillips, a lead prosecutor on the case. The stuff has proven popular with teens and college-age kids, many of whom assume it’s safe because it’s being sold in a store, Phillips said.

But there are no standards, no quality control on production and no guarantees about the potency or safety of the products, Nettles said.

“That’s what makes it so particularly dangerous,” he said. “You don’t know what you’re getting into until it’s too late.”

According to the National Institute on Drug Abuse, synthetic marijuana has become the second-most-popular illegal drug among teenagers, landing more than 11,000 teens in the emergency room in 2010 with symptoms that included vomiting, racing heartbeat, elevated blood pressure, seizures or hallucinations.

Last year Gov. Nikki Haley signed into law a bill that bans hundreds of compounds used to make synthetic drugs, such as bath salts and fake marijuana, in South Carolina.

And just this month, the U.S. Drug Enforcement Administration made three more chemical strains of synthetic marijuana temporarily illegal under the federal Controlled Substances Act “to avoid an imminent hazard to the public safety.”

During the next two years the DEA will work with the U.S. Department of Health and Human Services to determine if these chemicals should be made permanently illegal.

Nettles said these moves and the recent Charleston indictments should eliminate any ambiguities or doubts about the legality of selling synthetic pot.

“It is no longer a gray area,” he said. “We view this as a problem that we are willing to commit resources to resolve.”

Attempts to reach the three stores’ owners were unsuccessful over the past week.

When a reporter visited Kelly’s Quick Stop, at 3359 Rivers Ave., last week, two employees said they didn’t know any details surrounding the indictment and could not speak on behalf of the business.

The employees called the store’s owner and left a message, but The Post and Courier never received a return call.

Ibrahim and Abuamsheh have unpublished phone numbers and could not be reached for comment. No one answered the store’s phone on Wednesday.

At the Quick Stop convenience store at 890 Bacons Bridge Road, a man who gave his name only as Adam told a reporter he is the current owner of the business. He said he knew nothing about the indictments.

“I just been here from Tennessee almost 28 days,” he said. “I don’t know nothing about this subject.”

Adam said all the merchandise currently found at the store can be found at Sam’s Club, so he is confident that it is all legal.

The Tobacco Co., at 8510 Rivers Ave., was closed when a reporter visited last week, and no one answered its phone Wednesday. Patel does not have a listed phone number.

“Tried to come here many times,” one potential customer wrote on the store’s Facebook page last week. “No answering phone, no posted hours and often closed with no warning.”

“So how come you guys stopped selling the syn products and the ak products did the state band them ???” another customer wrote.

Federal authorities did not have statistics on the amount of fake pot seized in South Carolina, or estimates on how much of the stuff is being sold here. But despite the ongoing crackdown, it’s not hard to get, they said.

“I would say it is fairly prevalent,” Phillips said. “It’s not difficult to find and find in large quantities.”

Federal authorities say they are giving merchants and customers fair warning: That is about to change.

Reach Glenn Smith at 937-5556 or Twitter.com/glennsmith5.