EIGHT people have been hospitalised after reports of an unusual smell at the Swedish Security Service headquarters.

About 500 people were evacuated amid fears the smell was related to a gas leak.

3

3

Police are investigating the cause of the alert.

Local media earlier reported that sensors on the building’s roof had detected phosgene – a colourless gas with a suffocating odour, used to make plastics and pesticides.

The gas is known to have caused a vast majority of deaths during World War One.

Authorities have not confirmed the presence of phosgene at the security service building.

Emergency services were first alerted to the situation at 12.30pm (11.30am GMT) on Friday, after receiving a call from the headquarters of Sweden’s security service, Sapo.

The building, located just outside Stockholm city centre in Solna, was partially evacuated and barriers were set up hundreds of metres around the premises.

Eight people – including police officers who, according to cops, “noticed a smell when they arrived at the scene” – were hospitalised with breathing problems.

Pictures from the scene showed police officers wearing gas masks.

People in nearby buildings were reportedly told to shut their windows as a helicopter circled the area.

The nearest exit of a nearby motorway was closed and residents of homes in the sealed-off zone were refused access to their properties.

Schoolchildren were kept indoors, a teacher told broadcaster TV4.

Emergency services ended their operation and removed barriers about 4.30pm this afternoon.

Following early fears of a gas leak, the security service confirmed that no gas was detected inside or outside the building.

3

Download our fantastic, new and improved free App for the best ever Sun Online experience. For iPhone click here, for Android click here.