Europeans spend more than $27 billion annually on illicit drugs, according to a new report by the European Union (EU). Marijuana accounts $10.6 billion, while heroin accounts for $7.7 billion, the Associated Press reports.

Terror cells may finance some of their activities through drug dealing, the report warns. Europol Chief Rob Wainwright said in a news release, “Illicit drug production and trafficking remains one of the largest and most innovative criminal markets in Europe. As it grows more complex and becomes entwined with other forms of crime, and even terrorism, it represents a key threat to the internal security of the EU.”

The report warns that the drug trade could be viewed as a “gateway for radicalization,” by pushing drug offenders toward radical views in jail. “The impacts that drug markets have on society are correspondingly large and go beyond the harms caused by drug use. They include involvement in other types of criminal activities and in terrorism,” the report stated.

According to The Wall Street Journal, the report cites Morocco as a growing source of powerful cannabis resin. The report also found there is an increasing shift to maritime container trafficking of heroin. Central America is a growing supply source for cocaine consumed in Europe, according to the EU report.

One hundred new synthetic drugs were marketed in 2015 alone. EU authorities are now monitoring more than 560 such substances. “With increased availability, harms have increased such as acute, sometimes fatal, poisonings,” the report said.