Turkey has blocked all access inside the country to the online encyclopaedia Wikipedia.
Turkish media said authorities had asked Wikipedia to remove content by writers “supporting terror” but the site had not responded to the demands.
Turkey has temporarily blocked social media sites including Facebook and Twitter in the past, usually following protests or terror attacks.
The Turkish government has previously denied censoring the internet, blaming outages on spikes in usage after major events.
Wikipedia has also faced censorship in other countries, including a temporary ban in Russia, and repeated crackdowns in China.