DULUTH (AP) -- The Last Place on Earth shop in Duluth is suing over the government's plan to crack down on synthetic marijuana.

Store owner Jim Carlson says he has joined three similar Twin Cities businesses in a lawsuit against the Drug Enforcement Administration and the U.S. Department of Justice.

Carlson says they are asking a federal court in Minneapolis to block the DEA's move to outlaw five of the chemicals in synthetic marijuana, which is sold as incense.

In November, the DEA issued an emergency order to outlaw the chemicals after receiving increasing numbers of bad reports - including seizures, hallucinations and dependency.

Carlson has said the incense accounts for half of his sales. He already has challenged a city ordinance banning its sale.

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