Hacker group Anonymous said on Thursday it has launched DDoS (distributed denial of service) attacks on some Turkish government websites, in protest against government plans to introduce Internet filtering. The move comes a few days before Turkey holds parliamentary elections on Sunday.

By late Thursday, the site of Telekomünikasyon ?leti?im Ba?kanl??, the Internet regulator that drew up the filtering plan, was not accessible.

In launching the DDoS attacks, Anonymous may have run into opposition from hacker groups in Turkey who threatened to hack Anonymous sites, according to reports. Anonymous' news site, for example, was not accessible late Thursday. The group did not respond to a request for comment. Turkey's Information Department was also not immediately available for comment.

Turks are protesting against new Internet rules that comes into effect from August 22, and will require users to choose one of four filters before accessing the Internet.

In a petition on Avaaz.org, an online forum for mobilising support for a cause, petitioners called on Turkey's Information and Communication Technologies Authority, commonly known as BTK, to withdraw any regulations that include mandatory content filtering for Internet users and immediately reverse the new "Rules and Procedures on the Safe Use of the Internet".

In a statement online, Anonymous said that the Turkish government is taking censorship to a new level. The new filtering systems will make it possible to keep records of everyone's Internet activity, it added.

On Twitter, Anonymous claimed that four sites in Turkey were inaccessible. But two of them, that of the country's meteorological service and the ministry of national education, appeared to be up and running at time of writing.

Anonymous hacked the site of an Indian government IT organisation earlier this week, in protest against corruption and government action against protesters.