The International Criminal Court (ICC) said it was hit by a “sophisticated and targeted” cyberattack as NATO leaders gathered in The Hague for a summit last week.

The ICC, which is based in The Hague, said it detected the incident “late last week” and had contained the threat. “A Court-wide impact analysis is being carried out, and steps are already being taken to mitigate any effects of the incident,” the court said in a statement on Monday.

The Hague was the scene of the NATO Summit early last week. Dutch cybersecurity authorities reported a series of cyberattacks known as distributed denial-of-service (DDoS) attacks against local governments and other institutions in the run-up and during the summit. Those attacks, limited in impact, were claimed by known pro-Russian hacktivist groups online.

A power outage also caused massive disruption to train traffic in the country last Tuesday. Dutch authorities said they were investigating the incident and the country’s justice minister said he couldn’t rule out sabotage as a possible cause.

The ICC in 2023 also reported a hack of its computer systems it believed was an attempt to spy on the institution.

The global tribunal has recently come under scrutiny after it issued arrest warrants for Israeli Prime Minister Benjamin Netanyahu and his former defense minister, Yoav Gallant, over Israel’s military campaign in Gaza.

The U.S. Trump administration has slapped sanctions on the court’s Chief Prosecutor Karim Khan in response to the arrest warrants. Khan also lost access to his email provided by Microsoft in May, in an incident that has galvanized a political push in Europe to wean off American technology for critical communications.