The Netherlands raised its threat level for the first time since 2019 on Tuesday, saying the likelihood of a terrorist attack in the country had increased in recent months.
The Dutch anti-terrorism agency raised the threat level to four, or “substantial”, on a five-step scale, citing the Israel-Gaza conflict as the cause.
“Organisations like ISIS and Al Qaeda are using the war in Gaza to urge sympathisers to carry out attacks in the West,” the National Co-ordinator for Counter-terrorism and Security said.
"These organisations are also calling for attacks in retaliation for acts of desecration to the Quran in various European countries. Given this context, individuals or small groups within the [extremist] movement may feel inspired to commit acts of violence."
The events have had a "mobilising effect" not only on Islamist extremists within the Netherlands, but also on other radicals outside the movement, it said.
"Lone attackers are often more difficult to recognise than groups," the agency said.
“Attacks and arrests in France, Germany, Belgium and the United Kingdom since early October illustrate the risks posed by radicalised individuals who are inspired by current events and terrorist organisations.”
If the agency were to receive information about a specific attack being planned in the Netherlands, it would raise the threat level to five, or “critical”.
Attacks have happened recently in neighbouring European countries.
Earlier this month, a 23-year-old German-Filipino tourist was fatally stabbed near the Eiffel Tower in Paris.
The man accused of carrying out the attack is under investigation on charges of murder and attempted murder in connection with a terrorist organisation.
He had been under surveillance for suspected radicalisation and had been convicted and served prison time for a planned attack that never took place.
In October, authorities in Brussels shot and killed a Tunisian citizen hours after he shot three Swedish football fans, killing two of them, and posted a video online in which he claimed credit for the attack.
Sweden raised its terror alert to the second-highest level in August after a string of public desecrations of the Quran sparked angry demonstrations across Muslim countries and threats from militant groups.
