Sweden’s Civil Contingencies Agency (MSB) has warned that the country’s nuclear shelters are insufficient to protect the population from a potential attack.

The country currently has 65,000 shelters with space for seven million people in the event of an attack.

As reported by The Local, it has been 15 years since new shelters were last built, and the population reached the 10m mark earlier this year, so the country needs to bolster its protection.

MSB’s report, which was put together at the request of the government, recommends that a further 50,000 bunkers should be built over a ten-year period starting in 2019. The project is expected to cost two billion kronor.

The areas set to be prioritised are Stockholm, Norrbotten county in the far north, the island of Gotland, and the Öresund Region encompassing Malmö.

Meanwhile, existing shelters need to be refurbished. This will include improving ventilation and updating respiratory equipment available to the population, for example.

According to The Local, Sweden’s shelters are housed in residential buildings, office blocks, and some more unusual locations. They are designed to protect residents from “all weapons that could be used”, according to the MSB, including shock waves and shrapnel as vapor deposition, biological weapons, fire, and ionizing radiation.