LINCOLN, Neb. (AP) — A Nebraska senator is calling for further investigation of synthetic marijuana following a recent rash of overdose cases in Lincoln.

Sen. Beau McCoy of Omaha said Tuesday he will introduce an interim legislative study to address the synthetic drug known as K2. Emergency responders in Lincoln have reported more than 100 overdose cases in the last few weeks, and many users ended up in emergency rooms.

K2 is a synthetic plant product sprayed with dangerous chemicals to mimic the high of natural marijuana. McCoy has introduced legislation over the last several years to clamp down on synthetic drugs, but manufacturers continue to change the product to skirt state laws.