European police seized drugs worth €85 million and arrested hundreds of suspects during a continent-wide sweep last month, Europol announced Friday.

The operation called "Joint Action Days 2019" in mid and late September not only targeted the trade in synthetic drugs and new psychoactive substances, but also human trafficking, migrant smuggling and environmental crime, the Hague-based law agency said.

Led by the Polish Central Bureau of Investigation and joined by 15 other member states, the sting conducted by more than 37,000 officers "targeted drug traffickers across Europe," Europol said.

"These activities brought in an important hit on drug trafficking networks, pulling drugs worth more than €85 million out of the illegal market," Europol said, quoting preliminary results.

This was a "huge hit to the European drug market," it added.

The haul included the seizure of 11.3 tonnes of MAPA precursor, used in the manufacturing of amphetamines.

Depending on how it was made, this quantity of MAPA drug base would have been enough to produce 6.3 tonnes of amphetamines, a mood-altering drug "worth nearly €63 million on the European market."

Police also confiscated 1,3 tonnes of cocaine, 19,600 ecstasy pills, 22 kilogrammes of cannabis and 1,107 cannabis plants, 10.6 kilogrammes of amphetamines and six kilogrammes of the drug MDMA.

In all, police arrested 411 people and identified 54 potential victims of human trafficking.