Hundreds of Twitter accounts, from businesses and media outlets to celebrities including Justin Bieber were hacked Wednesday and branded with the Turkish flag and nationalist pro-Turkish messages.
One tweet appears to show a swastika and Turkish hashtags which translated mean "Nazi Germany" and "Nazi Holland." The tweet appears to be in support of Turkish President Recep Tayyip Erdogan.
A wide range of Twitter accounts appeared to have been hacked with the same message, including Forbes, BBC North America, World Meteorological Organization, bitcoin wallet Blockchain, German soccer club Borussia Dortmund, U-Haul, tennis star Boris Becker, Justin Bieber's Japanese account and the Atlanta Police Department.
Messages also mentioned the date April 16, when Turkey will hold a constitutional referendum seeking to give more power to the president.
It comes after rising tensions between Turkey and the Netherlands. Last week, Erdogan branded the Dutch government "Nazi remnants and fascists" after a Turkish minister was blocked from visiting the country's consulate in Rotterdam. Erdogan responded by warning the Netherlands it would "pay the price" for its actions.
The war of words continued Tuesday when Dutch Prime Minister Mark Rutte told CNBC that Erdogan was "totally off the mark" when he likened the Dutch to Nazis and had behaved in an "increasingly hysterical" manner.
Many of the accounts that were hacked have seemed to have taken back control.
A number of Twitter users are claiming that a third-party analytics app called Twitter Counter was compromised, which allowed hackers to send out tweets from anyone using that software.
A Twitter Counter spokesman said the company was aware of the situation and had begun to investigate.
"Before any definite findings, we've already taken measures to contain such abuse of our users' accounts, assuming it is indeed done using our system - both blocking all ability to post tweets using our system and changing our Twitter app key," the spokesman told CNBC by email.
"One thing is important to note - we do not store users' Twitter account credentials (passwords) nor credit card information. The abuse risk is limited to posting or following on Twitter and as I've mentioned - the first part is already contained."
Twitter said it was aware of "an issue" affecting a number of users and pointed to a page on its website giving advice on how to stay safe.
"Our teams are working at pace and taking direct action on this issue. We quickly located the source which was limited to a third party app. We removed its permissions immediately. No additional accounts are impacted," a spokesman told CNBC by email.
This article first appeared on CNBC.com.