Authorities in Turkey are blocking access to Twitter after accusing the microblogging service of failing to respond to court rulings ordering the removal of links.
Anyone trying to access the service is being redirected to a statement by Turkey's telecommunications regulator that cites a court order to apply "protection measures" on the website, the BBC reports.
Turkish telecoms watchdog BTK said the Twitter ban was in response to complaints by citizens that the social media platform was breaching privacy, The Guardian reports.
The watchdog said it had asked Twitter to remove some content, but it had failed to do so.
"Because there was no other choice, access to Twitter was blocked in line with court decisions to avoid the possible future victimisation of citizens," BTK said.
But reports suggest the move is linked to prime minister Recep Tayyip Erdoğan's vow to "wipe out Twitter" following damaging allegations of corruption in his inner circle, which he denies.
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In recent weeks, some Twitter users have posted voice recordings and documents purportedly showing evidence of corruption.
In response, Erdoğan had made repeated threats to shut down social media sites, and two weeks ago said he was considering a total ban on sites such as Facebook and YouTube.
Turkey blocked access to YouTube in 2008 for two years over videos that were deemed insulting to the country’s founder, Mustafa Kemal Ataturk.
Twitter, which reportedly has about 10 million users in Turkey, has so far made no public comment on the government-imposed block.
However, Twitter has published a message telling users in Turkey that it is possible to send tweets using mobile phone text messaging.
Twitter users in Turkey have also been sharing information to help others affected by the ban, such as private protocols that can be used to hide an internet user's location and so circumvent the block.