The Ministry of Parliamentary Reforms and Mass Media ran an insertion in the state-owned Daily News today, warning websites that they must register before the end of this month or will be considered "unlawful".
The ministry in the advertisement, however, did not say under what law it required websites to register.
The prescribed Application for Registration of News Casting Websites demanded to know the names, addresses and telephone numbers of all contributors.
They said the government which came to power promising media freedom has now revived the move to censor news websites.
The then Rajapaksa government's restrictions on news websites was seen as one of the main reasons for the popular democratic rise against the regime.
The media organisations claim that there was no law in the country which requires this action.