Police swarmed a Connecticut park near Yale University and searched people’s homes for drugs Thursday in an effort to prevent more overdoses from a batch of synthetic marijuana blamed hospitalizing more than 70 people.

Social workers and mental health professionals also responded to the New Haven Green, where most of the overdoses happened Wednesday. Authorities described a chaotic scene where people were dropping to the ground unconscious, others vomiting and some becoming lethargic.

Officials said 76 people overdosed Wednesday and six more were treated Thursday. Officials weren’t certain whether Thursday’s cases involved the same batch of “K2” synthetic marijuana. No deaths were reported, and most of those brought to local hospitals have been discharged.

Synthetic marijuana, called “spice” and other names, usually is plant material sprayed with chemicals or other substances. It has been blamed for overdoses across the country. Some of the New Haven victims tested positive for the powerful opioid fentanyl, also blamed for overdoses, but authorities believe this week’s overdoses were caused solely by synthetic marijuana.