Turkish security officers stand on guard on the side of the road on July 15, 2016 in Istanbul, during a shutdown of the Bosphorus Bridge Twitter pointed Friday to "intentional slowing" of its service in Turkey, as reports surfaced that social media was being sidelined during a coup attempt.
An @TurkeyBlocks account that said it was mapping censorship in that country tweeted early in the day that it noticed "social media throttling," particularly Twitter, Facebook, and YouTube.
"We have no reason to think we've been fully blocked in #Turkey, but we suspect there is an intentional slowing of our traffic in country," Twitter said in a message fired off by its global policy team at an @policy account.
YouTube, a US-based online video sharing service, said "we are aware of reports that YouTube is down in Turkey, however, our systems seem to be functioning normally."
Facebook did not immediately respond to requests for comment.
Twitter, Facebook and YouTube have become powerful tools for sharing video of events, often in real time.
Turkish troops launched a coup attempt, with soldiers taking to the streets of Ankara and Istanbul.
State broadcaster TRT said the military had declared martial law and a curfew, in a statement signed by a group calling itself the "Council for Peace in the Homeland."
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