VIENNA (Reuters) – Austria’s parliament said on Tuesday that a Turkish Islamist hackers’ group had claimed responsibility for a cyber attack that brought down its website for 20 minutes this weekend.

Aslan Neferler Tim (ANT), or Lion Soldiers Team, whose website says it defends the homeland, Islam, the nation and flag, without any party political links, claimed the attack, a parliamentary spokeswoman said.

Relations between Turkey and Austria soured last year after President Tayyip Erdogan cracked down on dissent following a failed coup, and Vienna has since made a solo charge within the European Union for accession talks to be dropped.

On its Facebook page on Sunday afternoon, above a screenshot indicating the website was not loading, ANT said in Turkish: “Our reaction will be harsh in response to this racism of Austria against Muslims!!! (Parliament down).”

ANT says it has carried out “operations” against the pro-Kurdish Peoples’ Democratic Party (HDP), the Austrian central bank and an Austrian airport.

An Interior Ministry spokesman said on Tuesday that an investigation had begun into the cyber attack and, declining to elaborate further, noted that no data had been lost.

A parliamentary spokeswoman said: “ANT has claimed responsibility.” When asked if ANT was responsible, she said: “We assume so.”

The website was brought down after the server was flooded with service requests, a so-called DDoS-attack, similar to an attack last November that targeted the Foreign Affairs and Defense Ministries’ websites, a statement from parliament said.

DDoS attacks are among the most common cyber threats. One such attack targeted the European Commission’s computers in November.

The Vienna-based Organization for Security and Cooperation in Europe (OSCE) was also recently the target of a cyber attack.

(Reporting by Shadia Nasralla, Francois Murphy in VIENNA and Daren Butler in ISTANBUL; Editing by Louise Ireland)