Islamic State still poses 'grave threat' to EU states

The terror group is also evolving tactics to attack targets in Europe, which could see the use of deadly car bombs, the reported warned.

Militant attacks on EU member states have not yet involved "the use of home-made, commercial or military explosives in vehicle-bourne improvised explosive devices" as in Syria or Iraq, Europol said in a report issued in The Hague.

But "given the fact that the modi operandi used in Middle Eastern countries tend to be copied by terrorists operating in Europe... it is conceivable that jihadist groups will use this means at some stage," the continent's policing agency said.

IS also is adept at inspiring marginalised youths, some of whom may have mental health problems, and inciting them to carry out attacks.

"Estimates from some intelligence services indicate several dozen people directed by ISIS may be currently present in Europe with a capability to commit terrorist attacks," the report said, using an alternative acronym for IS.

The report also said that past attacks such as those in France and Belgium over the last two years show that extremists acting in the name of IS can effectively plan complex attacks.

Past attacks such as those in France and Belgium show that extremists acting in the name of IS can effectively plan complex attacks

Militants massacred 130 people in November 2015 in attacks on the Bataclan concert hall, a handful of bars and restaurants in eastern Paris, and France's national stadium.

In Belgium, suicide bombers struck Brussels airport and a metro station near the European Union headquarters on March 22, killing 32 people.

The 14-page report 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 in 2015.

"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.

The focus on so-called soft targets means that attacking critical infrastructure like power grids and nuclear facilities is "currently not a priority", the report added.

IS also is adept at inspiring marginalised youths, some of whom may have mental health problems, and inciting them to carry out attacks

Europol found that the consensus among intelligence agencies in EU member states is that "the cyber capabilities of terrorist groups are still relatively low," but said 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 attacks - should not be discounted."

Meanwhile, 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.

However the report said automatic firearms, knives and vehicles are more easily available and that "The effectiveness, ease of use and access of these weapons will continue to be relevant."