Twitter accounts belonging to high-profile media outlets, international brands and politicians worldwide were hacked on Wednesday, briefly showing posts in support of Recep Tayyip Erdogan, the Turkish president who is in a bitter standoff with European countries.
The government in Ankara and several countries, including the Netherlands and Germany, are at odds over whether Turkish politicians should be allowed to speak at political rallies in those states. Although the dispute centers on rallies for a referendum on Turkey’s Constitution, the brief hacks came on the day that Dutch voters cast their ballots in a general election. Separately, another online attack struck websites in the Netherlands that help people decide how to vote.
Mr. Erdogan has criticized the German and Dutch governments, accusing them of Nazism, after Turkish politicians were prevented from attending events in several European countries. Over the weekend, the Netherlands stopped Turkey’s foreign minister from landing in the country for a rally, and escorted the Turkish minister for families out of the country, citing risks to public order and security.
The Twitter hacking on Wednesday appeared to be related to the dispute between the NATO members. The defamatory messages in Turkish accused Germany and the Netherlands of having Nazi ties, and linked to a video of a speech by Mr. Erdogan.
While the online messages were quickly removed and control of the accounts returned to their owners, many of the organizations and policy makers moved to distance themselves from the tweets. It was unclear who had carried out the hacking.
“We temporarily lost control of this account, but normal service has resumed,” the British Broadcasting Corporation wrote on Twitter after one of its accounts was involved in the hack.
The problem may have originated with a hack to Twitter Counter, a third-party application employed by some account holders to keep track of their online followers. The start-up, which is based in the Netherlands, said on Wednesday that it was aware of the hacking, and that it had blocked its service’s ability to post from users’ Twitter handles.
In response, Twitter said that it was aware that the intrusion may have resulted from a third-party app.
“We quickly located the source,” Twitter said in a statement. “No additional accounts are impacted.”
On Tuesday, a different attack hit two websites set up to help voters choose between the Netherlands’ political parties on Wednesday.
The voter aid websites are not part of the official electoral process. But, concerned about the role hackers and “fake news” might have played in the United States election, the Netherlands government announced weeks ago that all ballots in Wednesday’s elections would be counted by hand. Previously, votes were counted digitally in part.
The attack, known as a distributed denial of service or DDoS, which typically involves flooding computer servers with online messages until they collapse, took the Kieskompas and Stemwijzer sites offline on Tuesday afternoon.
“We don’t know where it is coming from, but it is an organized attack coming from abroad,” said Anita de Jong, a spokeswoman for ProDemos, an independent government-funded organization that runs Stemwijzer. She said site of the origin of the attack was unclear.
Engineers from the Netherlands’ National Cyber Security Center and Google offered their help to the organizations that run the two websites, but by Wednesday morning, as Dutch voters took part in the country’s election, the sites were still struggling to function, and were not consistently available.