The threat of a terrorist attack in the Netherlands has increased slightly over the past few months but remains at level 4, or substantial, the government’s counter terrorism agency NCTV said on Tuesday.

Level four means there is a realistic likelihood of an attack. The risk was raised from three to four at the end of last year, in what was the first increase in four years.

The biggest threat facing the Netherlands is that of jihadism, the NCTV said, pointing out that its supporters have been fed propaganda footage of the war in Gaza and Korans being destroyed in the Netherlands itself.

In addition, some youngsters within the right-wing terrorist online environment also pose a threat, driven not by ideology but by “a lust for violence and compulsion to shock”. These groups, the agency said, are small but often have a large reach.

Nevertheless, if such ideas win broader acceptance, they will foster increasing intolerance of government and in time that could increase the likelihood of violence, the NCTV said.

Other minor threats are posed by the “anti-institutional movement” which is fueling distrust of democratic institutions and undermining trust in the democratic rule of law, but only a small group would be prepared to use violence.

In addition, left-wing extremism provides only a limited threat in the Netherlands, the report states.