"We don't change the threat assessment from day to day, rather it's more long term. It's based in part on publicly available strategic information – what's going on in the world," Säpo head Anders Danielsson told Sverges Television (SVT) in an interview on Thursday.
On October 1st, Säpo decided to raise Sweden's terror threat level by one step from low to elevated, equating to a shift from level two to three on an escalating scale of five.
The move was in response to a specific threat which has since passed to Swedish artist Lars Vilks for his drawings of the prophet Muhammad which were published in the Nerikes Allehanda newspaper.
However, new threats have emerged, leading Säpo to conclude that the country's terror alert status should remain elevated.
The decision comes from a new assessment, which takes place every six months, based on information from various sources.
"We have troops in Afghanistan and are aware that Sweden is on the map in a different way," said Danielsson.
While he refused to elaborate on the specifics of the threat, Danielsson did admit that Säpo failed to detect the suicide bomber Taimour Abdulwahab, who blew himself up in downtown Stockholm in December.
However, he refused to call the miss a mistake.
"It was our mission to prevent terror attacks in Sweden, but that it was a mistake in the sense that we didn't do our job, that's definitely something I won't say," he told SVT.