Twitter has become the latest front in a war of words that has pitted Turkey against the Netherlands and Germany.
Several prominent Twitter accounts were vandalized early Wednesday by hackers who posted images of the Turkish flag along with anti-German and anti-Dutch messages.
Amnesty International, Forbes, PBS Food, Starbucks Argentina, Justin Bieber Japan, the University of Chicago and the Atlanta Police Department were among the verified accounts that appear to have been compromised.
The hackers used inflammatory language and Nazi symbols, including the swastika, to attack the Netherlands and Germany. They also posted a YouTube video that featured clips of Turkish President Recep Tayyip Erdogan.
Twitter (TWTR) said it was working to address the issue, which has been traced to an unidentified "third party app." It said that no additional accounts will be impacted.
Some cybersecurity experts suggested that Twitter Counter, which helps users measure analytics, may be the third party app that was breached. The company said it is investigating the issue.
"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," Twitter Counter said in a statement.
Related: The Dutch economy is doing just fine. Why are voters so angry?
Tensions have flared in recent weeks between Turkey and the Netherlands.
Erdogan is trying to rally roughly 4.6 million expatriate Turks living in western Europe to vote in an upcoming Turkish constitutional referendum. Germany, Austria and Switzerland have sought to prevent referendum rallies taking place on their soil -- citing security and overcrowding concerns.
Tensions escalated this weekend after the Netherlands barred Turkey's top diplomat from entering the country to address a political rally. That set off ugly diplomatic feuding, name-calling and popular unrest.
Related: Why are Turkey and the Netherlands clashing?
Erdogan said the Netherlands is "sacrificing Turkish-Dutch relations." He likened the Netherlands to a "banana republic" and also called for sanctions.
"Nazism is still widespread in Europe," he said.
Meanwhile, an election in the Netherlands on Wednesday will pit a hardline anti-Islam, anti-immigration candidate against the incumbent prime minister. The dispute has become a major issue in the final days of the campaign.
-- Onur Çakir and Julia Jones contributed reporting.
