|Demonstrators wave Turkish flags during a protest in front of the Dutch Consulate in Istanbul|
The attacks, which appeared to be simply a form of political vandalism and used the hashtags #Nazialmanya or #Nazihollanda, took over accounts of high-profile CEOs, publishers, government agencies, politicians and also some regular Twitter users.
The account hijackings took place as the Dutch began voting on Wednesday in national elections seen as a test of anti-establishment and anti-immigrant sentiment held in the midst of a diplomatic spat with Turkey.
President Tayyip Erdogan has suspended high-level diplomatic ties with the Netherlands and branded the country’s citizens “Nazi remnants” for preventing his ministers at the weekend from addressing rallies of Turks living there.
Hijacked accounts featured tweets with Nazi symbols, a variety of hashtags and the phrase “See you on April 16”, an apparent reference to the date of Turkey’s planned referendum to grant Erdogan more powers.
The Twitter accounts hijacked included those of the European Parliament and the personal profile of French politician Alain Juppe.
They also included the UK Department of Health and BBC North America, both of which subsequently appear to have recovered, along with the profile of Marcelo Claure, the chief executive of US telecoms operator Sprint Corp, which remains hijacked.
Other accounts included publishing sites for Die Welt and Forbes and several non-profit agencies including Amnesty International and Unicef USA as well as Duke University.
The Twitter profile of BBC North America noted: “Hi everyone – we temporarily lost control of this account, but normal service has resumed”.
A Twitter spokesman said the company was aware the service was hacked and that it had begun to investigate: “We quickly located the source which was limited to a third party app. We removed its permissions immediately,” the statement said. It added that no additional accounts are affected.
At least some of the hijacked tweets appear to have been hooked up to Twitter Counter, a Netherlands-based Twitter audience statistics company. In a tweet on the company’s owntwitter profile, it acknowledged the service had been hacked.
“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,” it said, including the ability to post tweets through the Twitter Connect app.
Twitter Counter also was the target of a hack attack in mid-November that led some of the high-profile Twitter accounts linked to the company’s app to spew out spam tweets, including those of soccer star Lionel Messi and gaming sites Sony Playstation and Microsoft Xbox. At the time, it said it counted 2 million users.
The latest attacks appeared unrelated to low-level denial of service attacks against the websites of a Dutch web hosting company and the Rotterdam airport by a Turkish hacking group called Aslan Neferler Tim (Lion Soldiers Team).
The same hacking group appears to have been responsible for temporary outages in August and September last year of the sites of Austrian institutions including the Vienna airport, the national parliament and Central Bank last year.
Those attacks occurred in the midst of a diplomatic row that followed Austria’s calls for European Union accession talks with Turkey to be dropped.