From Friday, February 12th, nobody leaving Tyrol will be able to do so without a negative test.
The measure will be in place for ten days.
According to Austrian media, “one of the largest police operations in recent years is underway” as a result of the declaration.
Police will monitor the Tyrolean border with other Austrian states as well as neighbouring countries Germany and Italy.
The Austrian armed forces have also been called in.
Tyrol on Monday laid out a range of potential measures to be put into place to prevent the order being made, however this appears to have been insufficient.
Tyrol has seen more than 400 cases of the South African variant of the coronavirus. The variant is believed to be more infectious than known variants, while also being more resistant to vaccines.
The Austrian government is expected to confirm the measures in a press conference on Tuesday afternoon.
'The biggest outbreak in Europe'
“The outbreak of the South African variant in Tyrol is the biggest currently known of in the European Union,” Chancellor Sebastian Kurz told a press conference.
There have been 293 confirmed cases of the highly transmissible variant in the region, with more than 100 further suspected cases, he said.
The majority of the cases are in the district of Schwaz, where a mass testing programme will now be carried out.
The requirement for a negative test result not older than 48 hours old to leave Tyrol will be in force for 10 days, Kurz said.
“We must do all we can to prevent or at least slow down the spread of the variant,” he said.
Interior Minister Karl Nehammer said fines of up to 1,450 euros ($1,750) could be levied on those not complying with the test requirement.
Travel from East Tyrol, which is not contiguous with the rest of the region, is exempt from the test requirement.
Kurz said the variant presented an “enormous challenge” because currently available vaccines are less effective against it.
Kurz's government, and regional authorities in Tyrol, have come under criticism for not reacting swiftly enough to the spread of the South African variant.
Kurz warns of emotional debate
“The debate in recent days has been very emotional, perhaps too emotional at times,” Kurz said.
He also sought to defend Tyrol's regional government, which is dominated by his own People's Party (OeVP).
“No one is to blame for the fact that there are mutations and no one can choose which mutations they have to confront,” Kurz said.
Tyrol has also come under the spotlight after reports emerged in recent weeks of scores of foreign skiers using loopholes in Austria's coronavirus rules to travel to the country's renowned ski resorts, many of them in Tyrol.
Austria's government allowed ski lifts to reopen just before Christmas, maintaining that outdoor sports posed little transmission risk.
Austria eased its third coronavirus lockdown on Monday, with schools, shops and museums reopening, albeit with strengthened mask and testing requirements.
The steps towards easing the lockdown came even though Austria's daily infection rate has remained stubbornly around the 1,000 mark in recent days.
The nation of 8.8 million people has had 426,093 confirmed cases, of whom 8,071 have died.