No one was injured in the relatively powerful explosion that took place in a living room in the reception centre. The explosion caused serious structural damage, however - including blowing out multiple windows and damaging walls.
Two foreign men were arrested and charged in the case and were expected to be questioned by police on Wednesday.
“They are indicted in the case based on the circumstances of the events and because they were located in the room where the explosion took place,” Western Police District spokesman Frode Kolltveit said on Tuesday evening.
Exactly what caused the explosion, which occurred just after 5.30pm on Tuesday, was not known as of midday on Wednesday.
“People from [the police] bomb squad and crime scene technicians were there last night. They found no traces of explosives, so there will be further investigations throughout the day [on Wednesday] to determine the cause of the explosion,” police spokesman Arve Samsonsen told NTB.
Police told NTB that investigators believe the explosion probably occurred in or around a stove. But what the stove had been used for is not known, nor do police know for sure who was involved. It was also not immediately known if the explosion was caused by chemicals or something electronic.
Between 15 and 20 people live at the asylum centre and they were evacuated from the site.