Updated

Federal agents say they have broken up a smuggling ring responsible for most U.S. distribution of a leafy stimulant called khat, which is illegal in America, but commonly used in East Africa and parts of the Arabian peninsula.

Prosecutors announced the indictment of 44 people Wednesday on charges that they helped bring 25 tons of the plant into the United States in recent years.

All but 14 of the suspects were under arrest after a series of sweeps in several states. Some five tons of the drug, worth $2 million, have been seized by agents during the 18-month investigation, authorities said.

U.S. Attorney Michael Garcia said the case signals that law enforcement agents take khat smuggling seriously.

Largely unknown to Americans, khat is a common and socially accepted drug in Yemen, Somalia, Kenya and Ethiopia.

Users chew it, like loose tobacco, and generally experience a mild buzz that lasts for about 90 minutes. It can cause an elevated heart rate and blood pressure, as well as a feeling of euphoria.

In some non-Arab or African countries where the drug has made a showing, it is viewed as a social ill, albeit an acceptable one. England considered a ban on khat this year, but decided against it.

It is illegal in the U.S. because it can contain two controlled substances: cathonine, which is found in very fresh khat leaves, or cathine, a less potent chemical that turns up once the plant dries.

The wave of arrests Wednesday nevertheless bothered Omar Jamal, the executive director of the Somali Justice Advocacy Center in St. Paul, Minnesota. He said the drug is routinely used among immigrant Somalis in the U.S.

"I think it is very sad because khat is linked to Somali culture," he said. "It's part of the social system."

Investigators said the defendants arrested Wednesday mailed khat to the United States in packages or sent it with couriers aboard commercial airlines. From New York, it made its way to Ohio, Minnesota, Maine, Massachusetts, Utah, Washington state, Illinois and Washington D.C.

Some amounts of the drug were also smuggled into the U.S. inside United Nations diplomatic pouches, which are not subject to inspection by customs agents.

People have been arrested for khat possession in the U.S. for years, but the busts have increased in frequency as the Arab and East African immigrant communities have grown.

In a related case, a federal grand jury in Seattle indicted 18 people on khat importing charges. The six month investigation led to the seizure of 1,000 pounds of the drug.

Gilbride said the drug is still seldom distributed outside those communities, but is no less of a public health risk.

Medical studies have yet to conclude how bad khat can be to someone's health, but some research has linked it to depression, hyperactivity or hallucinations among longtime users.