Police spokesman Thomas Fuxborg said on Monday evening that the teenager had been arrested on suspicion of murder. He added that the motive was not immediately clear, but noted that a knife had been found at the asylum accommodation in west Sweden.
"It was messy, of course, a crime scene with blood. The perpetrator had been overpowered by other residents, people were depressed and upset," he told the TT news agency.
"These kinds of calls are becoming more and more common. We're dealing with more incidents like these since the arrival of so many more refugees from abroad," the officer said in a separate interview with AFP.
The victim was attacked earlier in the day and taken to a nearby hospital but died of her wounds. Other residents at the home restrained her alleged attacker while officers arrived.
She was named on Tuesday by Swedish media as 22-year-old Alexandra Mezher, who report that her family is originally from Lebanon.
"I felt a big shock. I was so sad," one of her cousins told the Expressen tabloid.
"It is so terrible. She was a person who wanted to do good, who wanted to be good. And then someone murdered her when she's doing her job," a different cousin was quoted as saying.
A tweet from a regional newspaper, showing a picture of Mezher
Police would not comment on the identity or nationality of the alleged attacker, except to say that he was a young man who was a resident of the centre for 14- to 17-year-olds in Mölndal, near Gothenburg.
Staffan Alexandersson, social worker and spokesperson for Living Nordic AB, which runs the accommodation, described the incident as a "horrible and tragic event".
"We regret what happened, and we're working right now in the crisis team to deal with both staff and children," he told TT, adding that all residents had been moved to alternative accommodation.
Sweden's Prime Minister Stefan Löfven also condemned the attack during a visit to the area on Monday.
He said it was "too early" to draw any conclusions about the incident but said that he would work to ensure that staff and residents at refugee housing could feel safe.
"Many of those young people who come to Sweden have had traumatic experiences and there are no easy answers," he told reporters.
Sweden's Prime Minister in Mölndal on Monday. Photo: Adam Ihse/TT
The stabbing took place on the same day as National Police Commissioner Dan Eliasson requested 4,100 additional officers and support staff to help fight terrorism, carry out migrant deportations and police asylum accommodations.
"We are forced to respond to many disturbances in asylum reception centres. In some places, this takes significant police resources. This was not the case six months ago and it means that we won't be able to respond as effectively in other areas," Eliasson told TT.
According to the Swedish Migration Agency, the number of threats and violent incidents at asylum facilities more than doubled from 2014 to 2015 as Sweden witnessed a record number of migrant arrivals.
In 2014, there were 148 incidents and in 2015 that number jumped to 322. Arson attacks targeting asylum shelters have also surged, with at least two dozen centres reduced to ashes or damaged by fire last year.
A country of 9.8 million, Sweden took in more than 160,000 asylum seekers in 2015, which put it among the EU states with the highest proportion of refugees per capita. Of those around 35,000 were unaccompanied minors arriving in the country.