Six Amsterdam taxi drivers were arrested during the early hours of Sunday morning for driving under the influence of drugs. The police had a total of 55 taxi drivers take a drug test. The six arrested drivers were taken to a police station for a blood test, NOS reports.

The blood samples were sent to the Netherlands Forensic Institute to confirm whether the drivers were really under the influence of drugs. What drugs they are suspected of using, was not disclosed.

The police also fined a number of taxi drivers for other violations. Two fines were issued for drivers refusing a customer, presumably because the drivers considered the rides too short to be worth their while, according to the broadcaster.