The basement was a choice location for after parties.
The raid started at 7AM after the police received a tip off. Seventy officers checked the 120 people present.
The police discovered 13 grams of speed, 30 XTC pills, 5.9 grams of cannabis, liquid XTC, GHB, MDMA and ketamine.
A further 170 XTC pills and over 30 grams of cocaine were recovered from the floor.
One person was armed with a knife and two others were on the run for the police.
A police spokesman told VRT News: "We want to respond quickly to problems that threaten the safety and viability of the feasts. This is our all round approach."
The basement is being closed because the quantities of drugs found pose a threat to public safety. The basement was rented out to an organiser of after parties. The café upstairs is not affected by the closure and isn't linked to the drug abuse.