A Duluth head shop known for its controversial sales of synthetic drugs stopped selling the substances on Thursday as a city ordinance banning the product took effect, the Duluth News Tribune reports.

The store, called Last Place on Earth, has been subject to much controversy as synthetic drugs, chemical compunds made to mimic the effects of drugs like methamphetamine, marijuana and hallucinogens, have come to public attention as a problem in recent years. The Tribune also reported the store's owner Jim Carlson was assaulted on Wednesday night by a woman who had previously bought synthetic marijuana at the store.

Both incidents come days after a legislative committee set off to tackle Minnesota's synthetic drug problem. The committee is led by Rep. Erik Simonson, DFL-Duluth, and aims to improve state laws regarding synthetic drugs.

Simonson and the committee will present its findings and plans to the full Legislature during the 2014 session.

Synthetic drugs are banned under state and federal laws, but are still sold as "incense" in some shops and can be difficult to prosecute in court.