So-called Islamic State is likely to carry out new attacks in the European Union in the near future, probably targeting countries that are members of the US-led coalition fighting the extremist organisation in Syria and Iraq, according to EU police agency Europol.
"Estimates from some intelligence services indicate several dozen people directed by IS may be currently present in Europe with a capability to commit terrorist attacks," according to the report, which draws on counterterrorism intelligence from around Europe and also cites media reports and previously publicised calls by IS leaders for attacks.
IS is also adept at inspiring marginalised youths, some of whom may have mental health problems, and inciting them to carry out attacks.
The report warns that tactics the group uses in Iraq and Syria - such as car bombings - could be deployed in Europe. It said that attacks such as those in France and Belgium over the last two years show that extremists acting in the name of IS can plan complex attacks.
France and Belgium are among European nations that have joined the US-led coalition against IS. Others include the UK, the Netherlands and Denmark. Germany's military also is involved, but not in combat operations.
Europol also noted a shift in attacks from symbolic targets like police officers and military personnel to indiscriminate attacks on soft targets, such as the Paris attacks.
"Indiscriminate attacks have a very powerful effect on the public in general, which is one of the main goals of terrorism: to seriously intimidate a population," the report said, adding that the focus on soft targets means that attacking critical infrastructure like power grids and nuclear facilities is "currently not a priority".
Europol said the consensus among intelligence agencies in EU states is that "the cyber capabilities of terrorist groups are still relatively low", but added that "the possibility of terrorist-affiliated cyber groups engaging in cyber warfare sponsored by nation states - those with capacities to engage in this type of attack - should not be discounted."
The report said a police raid in Morocco in February may have thwarted a possible attack by an IS cell using chemical or biological weapons, raising the spectre that such weapons also could be used in Europe, although the report said automatic firearms, knives and vehicles are more easily available and the "effectiveness, ease of use and access of these weapons will continue to be relevant".