Police shot dead one attacker, a man wearing an explosives belt that turned out to be fake.
Holidaymakers returning from Croatia, Austria and Trinidad and Tobago must now self-isolate for a fortnight.
His comments came after Croatia and Austria were dropped from the UK's list of safe travel corridors.
Scotland also adds Switzerland to list north of border amid a spike in Covid-19 cases abroad.
As some European nations reveal plans to gradually reopen society, Britain and France say even discussing lifting coronavirus restrictions would be a mistake.
Two separate avalanches within hours of one another led to the deaths.
He handed himself into police early Sunday morning.
Getting intimate with cows can have "serious consequences", Austria's tourism minister has warned.
But Jewish and Sikh head coverings will not be affected.
One person has died.