Justice Minister Ivo Opstelten called the attack on the court in Amsterdam’s central business district an act of “incredible violence” and “an attack on the rule of law,” Dutch news agency ANP reported.

No one was injured in the explosion in the early hours of Wednesday before staff arrived for work. Police said they were looking for at least two suspects.

The courthouse heard the case of populist politician Geert Wilders, who was acquitted of inciting hatred of Muslims in June.

“We usually handle 40-50 cases a day — civil cases, criminal cases. We don’t know if the explosion is related to any case. For today, we had no high-profile cases scheduled,” said Anke Poul from the court’s press office.

Court cases continued on Wednesday despite the damage and disruption.