Turkish authorities on Saturday blocked access to online encyclopedia Wikipedia, an internet monitoring group said, the latest in what government critics say is a crackdown on free speech on the Internet.

A block on all language editions of the Wikipedia website was detected at 8:00 a.m. (0500 GMT) on Saturday, monitoring group Turkey Blocks said on its website.

"The loss of availability is consistent with Internet filters used to censor content in the country," it said.

When attempting to access the webpage using Turkish Internet providers, users received a notice the site could not be reached and a "connection timed out" error.

Turkey Blocks and Turkish media, including the Hurriyet Daily, said the site has been blocked under a provisional administrative order that would need to be backed by a full court order in the next days.

"After technical analysis and legal consideration based on the Law Nr. 5651, an administrative measure has been taken for this website," Turkey's Information and Communication Technologies Authority was quoted as saying.

Monitoring groups have accused Turkey of blocking access to social media sites such as Twitter or Facebook, particularly in the aftermath of militant attacks.

Savvy Internet users frequently resort to the use of VPNs to get around these bans, although there have been complaints that the use of VPNs has now also started to be blocked.

The government has in the past denied that it blocks the Internet, blaming outages on spikes in usage after major events. But technical experts at watchdog groups say the blackouts on social media are intentional, aimed in part at stopping the spread of militant images and propaganda.

(Source: Reuters, AFP)