Police have apprehended a 15-year old Danish girl who recently converted to Islam, for keeping explosives at her home and inciting terror on social networking sites, reports said.

The girl whose name is being withheld was arrested last Jan. 13 at her home in a village of Kundbt on the island of Zealand, Denmark's TV2 reported, according to WND.

"A bomb squad was sent to the home, and an object removed via the basement,'' Danish tabloid BT reported, citing a witness.

On Thursday, Jan. 14, the girl appeared in court and was charged under Denmark's terror laws with "possession of explosives, detonation of explosives and sanctioning or encouraging terror," IBT reported.

The court appearance was reportedly held behind ''double-locked doors,'' meaning all information is withheld from the media and the public.

According to investigators, the girl's Facebook page indicated that she was part of the Danish group Hizb ut-Tahrir, which promotes the establishment of a pan-global caliphate governed under Sharia law.

Reacting to reports, Frank Jensen, Danish Security and Intelligence Service (PET), told TV2 that the incident was "unusual.''

"This is about a girl as young as 15. On top of that, there are the explosives. It is quite unusual,'' he said, RT reported.

He noted that the group, which the girl appears to have supported, has been into numerous controversies in Denmark. Last year, the group called for Muslims to boycott elections, saying they are incompatible with Islam. In January 2015, the group hit out a local policy to deradicalise Muslim youths, claiming it is "sad Western culture'' which needs to change.

In 2006, a spokesman for the Danish group was arrested after distributing anti-Semitic leaflets in Copenhagen which described suicide bombings in Israel as "legitimate'' acts of martyrdom, according to WND.

Denmark is among several European countries that have stepped up security after the Nov. 13, 2015 Paris attacks. At least 130 people were killed and more than 300 injured when the Islamic State jihadist group launched the attacks in the French capital.