NEW YORK — New York City's law department has been hit with a cyberattack that has forced officials to take the 1,000-lawyer agency offline while they investigate, officials said.

Mayor Bill de Blasio said Monday that he believes no information was compromised in the hack.

"We're still tracking down exactly who was behind it," de Blasio said on TV station NY1. The mayor added, "so far, we believe the defenses have held and the law department information was not compromised."

City officials said they disconnected the law department's computers from the city's network on Sunday after discoverying the cyberattack.

"As the investigation remains ongoing, the City has taken additional steps to maintain security, including limiting access to the Law Department's network at this time," de Blasio spokesperson Laura Feyer said in a statement.

Cyberattacks targeting government agencies as well as private companies have become an increasing threat, including last month's ransomware attack against Georgia-based Colonial Pipeline, which caused widespread gasoline shortages.