The incident occurred on Skansbron in Södermalm in Stockholm at around 8:30 a.m. on Monday.
A man in his 50s then sprayed a fire extinguisher inside a bus, even though there was no fire.
It seems that he sprayed the bus driver. We have no answer as to why he did it, says Daniel Wikdahl, police spokesman, to Aftonbladet.
Several people were on board the bus, but no one was reportedly injured.
The Skansbron had to be closed completely and according to the Swedish Transport Administration, the incident had a very significant impact on traffic.
The man who sprayed the fire extinguisher was taken into custody by police, who have opened a preliminary investigation into violence against an official, the police write on their website.
