By midday Friday, tweets were continuing unabated as users swapped instructions online on how to change settings. One enterprising user spread the word by defacing Turkish election posters with instructions on beating censors.
President Abdullah Gul was among those who circumvented the order, which he contested in a series of tweets. Gul, once a political ally of Erdogan, has spoken out against Internet censorship in the past, although last month he approved government moves to tighten controls over the Internet.
"I hope this implementation won't last long," he wrote.
Links to leaked recordings have been popping up on two Turkish Twitter accounts, including one in which a voice resembling Erdogan's instructs his son to dispose of large amounts of cash from a residence amid a police graft investigation. Erdogan, who denies corruption, said the recording was fabricated and part of a plot by followers of an influential U.S.-based Muslim cleric to discredit the government before March 30 local elections.
Erdogan has cast the elections as a referendum on his rule.
"Prime Minister Erdogan's move spells the lengths he will go to censor the flood of politically damaging wiretap recordings circulating on social media," said Emma Sinclair-Webb, senior Turkey researcher at Human Rights Watch.
Andrew Przybylski, a researcher at Britain's Oxford Internet Institute, said the ban appeared to be working through Domain Name System or DNS blocking, which was easy to work around.
He said many Twitter-hungry Turks manually changed the DNS settings on their computers and in their phones to point to Google's Domain Name System, which isn't affected by the ban.
Earlier, many users trying to access the network instead saw a notice from Turkey's telecommunications authority, citing four court orders.
Turkey's lawyers' association asked a court to overturn the ban, arguing it was unconstitutional and violated Turkish and European human rights laws. Turkey's main opposition party also applied for a cancellation.
"Turkey now stands along with countries such as North Korea, China, Saudi Arabia, Iran and Russia on Internet freedom," columnist Yavuz Baydar said in an email.
Twitter's (at)policy account earlier sent out messages telling Turkish users in both English and Turkish they could send out tweets by using short message service, or "SMS." It was unclear how those tweets would be viewable.
European Commission Vice President Neelie Kroes criticized the Twitter ban in Turkey a country that is seeking to join the European Union as "groundless, pointless, cowardly." Other EU officials also voiced concerns.
Lutfi Elvan, Turkey's minister in charge of transport and communications, said Turkey was merely obeying court orders although an Istanbul lawyers group argued the court decisions were about blocking access to websites deemed to be violating privacy not the entire website. The telecommunications authority accused Twitter of violating "personal rights and the confidentiality of private lives" and said access would be restored only when Twitter removes illegal content.
"Turkey is not a country that bans the Internet," Elvan said. "We have to stand together against insults and unlawfulness."
Technology Minister Fikri Isik said officials were holding talks with Twitter and that the ban would be lifted if an agreement is reached.
Turkish technology minister is quoted as saying that officials are holding talks with Twitter and that the ban will be lifted if some kind of an agreement is reached
The original source of the leaked recordings is unclear. The ban comes amid rumors and news reports that even more damaging recordings are about to emerge.
"Conspiracy or not, limiting freedom of speech is no way for the Turkish government to tackle a political crisis," said Sinclair-Webb of Human Rights Watch.
In Berlin, the German government's human rights commissioner, Christoph Straesser, called on Turkey to reverse the decision immediately, saying "limiting freedom of the press and opinion on this scale is unacceptable."
Britain's Foreign Office also expressed concern, saying that social media has a "vital role to play" in modern democracy and helps promote transparency and public debate.
Raphael Satter and Cassandra Vinograd in London, Raf Casert in Brussels and Geir Moulson in Berlin contributed.