At around 1.30am police were called to Ljusdalen, north of Sundsvall, where ambulance staff called out to help a woman with respiratory problems suddenly found themselves under siege.
“The healthcare workers locked themselves into the ambulance when they were prevented from driving away,” said police spokeswoman Eva Lindberg.
“The youths smashed the windscreen and aimed kicks at the ambulance,” she added.
The ambulance staff eventually managed to escape and the situation had calmed down by the time police arrived.
Just a few minutes earlier a 24-year-old man was stabbed in the thigh outside a party on Bergsgatan in the centre of town.
“A dispute out on the street turned violent and one man was slashed in the thigh with a knife. The injury is not thought to be life-threatening,” said police spokesman Stefan Edin.
A 22-year-old man has been arrested on suspicion of having carried out the attack.
Two girls also claim to have been assaulted on Bergsgatan, Expressen reports.