Turkey on April 29 blocked all access inside the country to the online encyclopedia Wikipedia, the communications agency said.
Turkey’s Information and Communication Technologies Authority (BTK) said it had implemented the ban on wikipedia.org, without making clear the reason for the move.
Turkish media said that the ban was imposed because Wikipedia had failed to remove content promoting terror and also linking Turkey with terror groups.
There was no indication as to when the ban might be removed, with a formal court order expected to follow in the next days.
A block affecting all language editions of the website in Turkey was detected from 8:00 a.m. after an administrative order by the Turkish authorities, the Turkey Blocks monitoring group, which watches internet restrictions in the country, said in a statement.
Residents in Istanbul were on April 29 morning unable to access any pages of Wikipedia without using a Virtual Private Network (VPN).
"The loss of availability is consistent with internet filters used to censor content in the country," Turkey Blocks said.
The BTK confirmed the ban in a statement but gave no details.
"After technical analysis and legal consideration based on the Law Nr. 5651, an administrative measure has been taken for this website wikipedia.org," it said.
No reason was given for the order to block Wikipedia. Other websites, including leading social media, appeared to be working normally.
But Turkish authorities had been in contact with Wikipedia to press for the removal of content by writers "supporting terror" and also claiming Turkey collaborated with terror groups, according to the media reports.
It said the site had failed to respond to the demands and, as a result, the ban was imposed.