A large undercover operation came to a head on Tuesday with the early morning arrests of dozens of Tel Aviv drug dealers who operated out of popular nightclubs, police said.

The operation was spearheaded by an undercover agent who spent 10 months infiltrating, and making purchases from, a loose network of drug dealers selling to Tel Aviv party-goers, Maariv reported on Tuesday. The drugs dealt included ecstasy, crystal meth, the “date-rape” drug GHB, and LSD.

According to the police, a “large part” of the transactions occurred in the restrooms or other areas of nightclubs, and some of those nightclubs were temporarily closed on Tuesday as a result of the investigation.

“In some cases, the drug transactions were made without the knowledge [of the nightclubs] but some were made with their tacit knowledge, which is why we want to close the clubs,” a police spokesman said.

The police arrested 29 people and confiscated 10 vehicles, NIS 20,000 and a bag of diamonds.