SAN DIEGO -- Federal raids on four San Diego medical marijuana dispensaries this week led to four arrests and the seizure of about 20 pounds of pot, it was reported Wednesday.

The businesses were allegedly not selling the drug within the limits of state Proposition 215, the 1996 initiative legalizing the sale of marijuana by prescription to seriously ill people, The San Diego Union-Tribune reported.

Drug Enforcement Administration and county Narcotics Task Force agents served warrants Tuesday at Answerdam on Convoy Court, Plan B Coastal Care Group on Adams Avenue, Chronic Care Providers on Daggett Street and Safe California Access on Murphy Canyon Road, DEA spokeswoman Eileen Zeidler told the Union- Tribune.

Four men, ages 26, 30, 35 and 59, were reportedly arrested on suspicion of marijuana sales and possession for sale.

The 30-year-old man was also arrested on suspicion of possessing the drug Ecstasy, according to the Union-Tribune.

The arrests culminated an investigation that took several months, Zeidler told the newspaper. Marijuana and marijuana-laced brownies, ice cream, chocolate and fruit bars were seized, along with a loaded handgun and thousands of dollars, she said.