Thousands of Twitter accounts -- including major verified ones like Duke University,Emmy Rossum nude sex scene in Shameless Reuters Japan, BBC America, Forbes Magazine and Amnesty International -- have been compromised with a swastika and a message in Turkish supporting President Recep Tayyip Erdogan.

The compromised accounts were under attack likely through their use of Twitter Counter, a third-party service that allows people and companies to track their popularity on the social network.

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The tweets all carried the same message: “卐 #NaziGermany👌#NaziNetherlands, a little👋#OTTOMAN SLAP for you, see you on #April16th.”

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The date reference is to the day Turkey will hold a key referendum that would grant even more powers to Erdogan. It also includes a link to a 4-minute, pro-Erdogan video on YouTube in which the president says: “If we’re going to die, let’s die like men."

The hashtags #Nazialmanya and #Nazihollanda (#NaziGermany and #NaziNetherlands) are in reference to Turkey's recent diplomatic beef with Germany and Netherlands.

Some profiles were changed into a Turkish flag or an Ottoman-style coat of arms:

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Twitter Counter said that they are aware of the situation and they started investigating the matter:

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“We’re aware that our service was hacked and have started an investigation into the matter. We’ve already taken measures to contain such abuse," the company said. "One thing is important to note - we do not store users’ Twitter account credentials (passwords) nor credit card information."

Twitter acknowledged the attack and confirmed the source was a third party application:

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Some accounts, which had been reinstated, still have an egg avatar: