The European Union agency that monitors drug use says it has detected a trend of escalating violence between gangs operating on the continent.
The development of new synthetic drugs and changes to traditional supply routes feeding drugs into Europe are bringing gangs into conflict, the agency said in its annual report published Tuesday.
The online sale of synthetic opioids creates new and unwelcome competition for heroin suppliers, for example.
These developments "create the conditions for disruptive criminal business models, greater competition and associated conflict, with the potential for an increase in harms, including violence, associated with the drug market,'' the report said.
"Drug market-related violence and intimidation is a growing concern in the EU,'' it added.
"In addition to firearms, including automatic weapons, the use of hand grenades and explosives in the context of drug-related violence appears to be increasing.''
European consumers increasingly have access to "a wide variety of high-purity and high-potency products," the agency said.
It added that these products are available at the same price or cheaper than over the past decade.
Europe's biggest market is for cannabis, worth at least 11.6 billion euros ($12.8 billion) in 2017, followed by cocaine with an estimated minimum market value that year of 9.1 billion euros ($10 billion).
The Lisbon, Portugal-based European Monitoring Centre for Drugs and Drug Addiction notes in its report Tuesday that illicit drugs are "the most valuable market" for criminal organizations in the EU.