According to The Local, Sweden has “64,000 bunkers — more than almost any other country in the world — capable of sheltering around seven million people.” The Civil Contingencies Agency has now begun upgrading 25 of the 80 largest shelters (in 2025, for instance, they will replace the 1996 filter-ventilation systems with modern ones).
In the event of military danger, strict rules apply in the shelters — unchanged since 1984 — including absolute obedience to authorities, bans on smoking, alcohol, and sex, rational use of water and food, and punishments for panic, up to and including the use of weapons.
The MSB (Swedish Civil Contingencies Agency) reassures citizens that state shelters (in addition to private residential ones) “provide protection against shock waves, radiation, fallout, thermal radiation, and chemical and biological weapons.”
https://www.thelocal.se/20250401/sweden-to-give-its-defence-shelters-a-100-million-kronor-makeover