Singapore's internet and phone regulator said that part of the government's website "www.pmo.gov.sg" had been compromised briefly with a mocking headline "it's great to be Singaporean today," appearing next to the group's trademark Guy Fawkes mask, News24 reports.
The PMO main website is still working normally, and the compromised section was quickly taken offline to restore the page, the report added.
The attack came a day after Lee said he would track down the group, if it attacks the city-state's technological network.
Earlier, a person claiming to be part of the group posted an online video in which he threatened to hack government websites.
Singapore's new internet rules have sparked anger in the blogging and social media community, which claims that the rules are designed to stifle free expression.
--ANI (Posted on 09-11-2013)