Counter-terrorism coordinator Gilles de Kerchove believes right-wing extremists and Islamic militants "could view attacks on medical personnel and facilities as highly effective, because they would generate a massive shock in society."
In a confidential briefing to EU member states obtained by the AP news agency, he said past experience shows "terrorists and violent extremists, aiming to change societies and governmental systems through violence, seek to exploit major crises to achieve their objectives."
Although there hasn't been an uptick in violence so far, de Kerchove warned Islamic State has "incited its supporters in the West to take advantage of the current crisis to stage attacks."
Groups such as ISIS are also ramping up their propaganda efforts, with the coronavirus lockdown meaning many people are spending more time online than they usually would.
"To increase their support base, violent extremists use people's insecurities, vulnerabilities and grievances, creating a simple narrative which 'explains' problems by blaming outsiders," de Kerchove wrote.