The accident occurred shortly after 4 p.m. Tuesday, according to police.
"The bus driver is seriously injured and has been taken by an air ambulance to hospital," says police spokesperson Ola Österling.
Seven people were transported to hospital, two of them seriously injured. Another nine people were taken to the nearest emergency room for treatment, according to Region Stockholm.
"The road curves and the bus drove straight into a facade there. So far we have no information that suggests that there are any pedestrians, that is, any person outside the bus or in the building who has been injured," says Österling.
It is unclear how many people were on the bus.
The police have opened a preliminary investigation into negligence in traffic and causing bodily harm. The bus, which is operated by Nobina, has been seized by police.
The bus is new and was safety-checked last night, according to Nobina's press service, which states that there is currently nothing to indicate the accident was caused by an illness.
Rail traffic was stopped in both directions at Liljeholmen after the accident, but resumed during the evening.
