Bloomington police say four people were arrested after investigators seized a large amount of synthetic marijuana and about $1 million from three tobacco stores.

48-year-old Ghassan Qahwaji, 39-year-old Ghiath Qahwaji, 35-year-old Hani Al-Maghayred and 32-year-old Hicham Rharabi were arrested Wednesday and charged with delivery of a controlled substance.

The arrests came after a more-than-six-month investigation by the Bloomington and Champaign police departments. Police say undercover officers were able to buy synthetic marijuana at two Global Tobacco stores in Bloomington and one in Champaign.

Police say they found large quantities of drugs packaged for sale and $1 million cash during searches of the stores and suspects' homes.

A Bloomington police spokesman says the drugs were being sold over the counter, with some in display cases.