Sweden has this month seen the number of new coronavirus cases once again start to rise, ending a decline seen since the start of the year.
Karin Tegmark Wisell from the Public Health Agency on Tuesday (Wednesday NZT) warned of "signs that compliance is less good than earlier", with people returning to workplaces and socialising more widely.
The country has so far recorded 1240 deaths per million people, a rate just behind that of France, and four times higher than its neighbour Denmark, which imposed much heavier restrictions.
The new "lockdown decree", which has been issued under the new law, will now go out to consultation, giving the Swedish parliament a week to reject or amend it. It will then come into effect on March 11, although this does not mean the new powers will necessarily be used.
Sweden has been ratcheting up coronavirus restrictions since a surge in infections in October, first tightening recommendations in the regions, but leaving them largely voluntary.
It has banned alcohol sales after 8pm, limited public gatherings to less than eight people, and recommended the use of face masks on public transport during rush hour.
At the start of January, the country then rushed through a new pandemic law which it used to impose a limit on the number of people who can enter shops and gyms.
Hallengren said that the new power to ban people from entering certain areas would help prevent overcrowding on beaches and in parks over the summer.
"Those who break this ban risk fins of up to 2000 kronor [NZ$334]," she said.