Several people are being investigated for serious fraud, the prosecutor's office in Feldkirch says, adding that the sums involved are believed to be less than US$10.99 million.

It applies to all adults, except pregnant women and those with a medical exemption.

The government initially wanted to cover everyone aged 14 and older, but now the measure only applies to adults, except pregnant women and those with a medical exemption.

Those who don't comply will face hefty fines of between 600 and 3,600 euros.

Austria says it will tighten restrictions again from Dec 27 to slow the spread of the Omicron variant.

A year ago, the constitutional court ordered the government to lift the existing ban on assisted dying, which is punishable by up to five years in prison.

Chancellor Karl Nehammer says his aim is to encourage as many as possible to get their first dose of vaccine.

The surgeon had marked the wrong leg of the 82-year-old patient for amputation ahead of the operation in May in the central town of Freistadt, only noticing the mistake two days after carrying out the surgery.

The Alpine nation plans to make Covid-19 vaccinations mandatory from Feb 1 next year, while the lockdown will start from Monday and will be evaluated after 10 days, according to the chancellor.

On Monday Austria became the first EU country to lockdown the unvaccinated in a bid to halt spiralling virus infection rates of around 12,000 per day in the country of 8.9 million.

Roughly 65% of Austria's population is fully vaccinated against Covid-19, one of the lowest rates in western Europe.

This means unvaccinated people will not be able to leave their homes unless they are going to work or shopping for essentials.