Using tear gas is common in these situations in several countries, but in Sweden, police have been banned from using tear gas outdoors up until now, reported Sveriges Radio (SR).

“Tear gas outside hasn’t been allowed at all, and that’s what the new rules mean, that it’s okay to use it in certain situations,” said Per Engström, head of the crime prevention division at the National Police Board (Rikspolisstyrelsen), to SR.

Swedish police have previously only been permitted to use the substance indoors, for instance when attempting to get people to leave a barricaded apartment.

“It’s really very hard to say when this might be used, but we’ve built in a number of decision levels to ensure that this is used in an absolutely correct manner.”

Parallel with the introduction of tear gas, rules for when and how police may use pepper spray have been tightened, after harsh criticism from the Ombudsmen for Justice (JO).

“For instance, restrictions will apply inside arrest cells, an area which has previously been totally unregulated. Vehicles are another example,” said Per Engström to SR.

The new rules for tear gas will come into effect on February 1.