Austria suspects a foreign country is behind a serious cyberattack on information systems at its Foreign Ministry that continued on Sunday, the ministry said.
"Given the type and seriousness of the attack we assume this probably concerns a state actor and not criminals," a ministry spokesman said.
He declined to give technical details about the assault or speculate on who might be behind it. "Experts have informed us that these things can last several days," he added.
The Austrian government reported the attack late on Saturday, noting other European countries have also been targeted for similar attacks in the past.
The attack came on the same day the environmentalist Greens party backed forming a coalition government with Sebastian Kurz's conservatives.
The ministry said "countermeasures" were in place while an inter-agency task force reviewed the situation. Services such as travel information were still available on its website.