Norway’s parliament has been targeted in what a top official characterized as a “significant attack.”

The apparent cyberattack against the parliament, known as the Storting, occurred over the past week and was announced on Tuesday. Marianne Andreassen, the Storting’s non-elected chief administrator, said that a “limited number” of lawmakers and employees fell victim to the attack, although details about the exact number of people affected were not revealed, according to Reuters.