Tests of a white powder discovered in an envelope at a Norwegian postal terminal did not show any harmful substance, police said Friday, while a similar find in neighbouring Sweden also triggered an alert.
In Norway, 44 employees were taken to hospital for check-ups after an envelope containing white powder burst open late Thursday at a postal terminal in Stokke, south of Oslo.
Tests by the Norwegian Defence Research Establishment conducted Friday showed that the powder was flour, police said.
Several employees suffered from irritated airways and skin rashes, but after observation all were able to leave hospital.
The envelope was covered in plastic and put in a secure room in line with procedures, police and the postal services told Norwegian broadcaster NRK.
Police said they knew who the addressee was, but declined to comment further. Efforts were ongoing to trace the sender.
The terminal was temporarily closed.
In Sweden, two suspicious envelopes were detected early Friday at a postal terminal on the outskirts of Stockholm.
Explosives experts were called to the terminal but left the site after securing the suspect envelopes. Laboratory tests were pending, police said.
No employees displayed any symptoms, but 29 people underwent decontamination procedures.
Police said they have launched an investigation into disseminating a poisonous or contagious substance, and threatening a group.