The police were alerted to a bang at an apartment building in Skarpnäck in southern Stockholm, where there was a fire in a stairwell. Several people were checked by medical services after the fire, but no one is said to be seriously injured.
Whether that incident can be linked to the explosion in Hässelby is too early to say, according to police.
"It's obviously something we always look at, but nothing I can comment on at the moment," says police spokesperson Carina Skagerlind.
A preliminary investigation into aggravated arson has been launched. One person has been arrested in the case, police said early Thursday morning. It is a man in his 40s who is suspected of involvement in the crime.
"We found the man outside after major police operations with, among other things, dog patrol and helicopter," says police spokesman Per Fahlström.