The court ruled to block them on the same day, citing alleged violation of a law that regulates the internet, according to Bianet, which added that it is among those websites.
However, it was not immediately clear when the court ruling would take effect, as some of the sites and accounts are still accessible.
The law stipulates that websites can be blocked over violations of national security and public order. The court would not elaborate exactly on which contents were deemed to be a security threat.
Among the sites to be blocked are the Twitter accounts of Oya Ersoy, an Istanbul lawmaker from the Peoples' Democratic Party (HDP), the left-wing music band Grup Yorum, and a group that clarified an ongoing court case into the 2013 Gezi Park anti-government protests.
On Twitter, Ersoy blamed a government policy to "silence the opposition," vowing to appeal the court decision.
President Recep Tayyip Erdogan's government last week introduced a new regulation to monitor all online broadcasters, including foreign news outlets and streaming platforms such as Netflix.
Turkey already blocks more than 245,000 websites, including Wikipedia, according to activists.
--------------------------------------------------------------------------------------------------