A 16-year-old Danish girl has been charged with planning a “terrorist” attack on two schools, one of them Jewish, after acquiring chemicals for bombs.

A police press release said the girl’s 24-year-old friend, who local media have said was a former fighter in Syria, had also been charged with complicity in preparing the bombs. Danish broadcaster TV2 said the girl had recently converted to Islam. She was arrested on 13 January and her friend the following day, accused of, among other things, having provided the girl with manuals for bombs.

Both have pleaded not guilty. They have not been named by the authorities or media, according to Danish practice and the court appearance was held behind so-called ‘double-locked doors’, meaning all information is withheld from the media and the public.

However on Tuesday, prosecutors publicly released details on the case, saying that both the girl, who was only 15 at the time of her arrest, and the 24-year-old man plotted to bomb the Jewish private school Carolineskolen in Copenhagen and the Sydskolen public school in the western Zealand town of Fårevejle.

The Danish intelligence service said the arrests had not changed their assessment of the security threat, classified as “serious” since February 2015 when a gunman killed two people in shooting attacks on a debating event and a Copenhagen synagogue before being shot dead himself by police.

According to TV2, the girl is Danish and had recently converted to Islam. One of the girl’s neighbours told the tabloid BT that her Facebook page indicated that she supported Islam and the idea of converting Danes to the religion. TV2 also reported that the girl’s profile page indicated that she was a member of Facebook group for ethnic Danish members of Hizb ut-Tahrir, an Islamic group that openly supports the establishment of a caliphate and that has been at the centre of numerous controversies in Denmark.

BT subsequently reported that the girl’s open Facebook profile didn’t attempt to hide her support of jihad. The tabloid wrote that on her way into court on Thursday, the 15-year-old girl “looked more like a schoolgirl than a terrorist”.

>A 24-year-old man who has previously fought alongside extremists in Syria was also arrested and detained in January in connection to the case.

Mid and West Zealand Police and the Danish Security Intelligence Service (PET) released a joint statement saying that the targeted schools had been contacted.

“Due to security concerns, PET cannot say what security measures the case has given rise to, but PET can say that it has not given the schools recommendations to make any changes in or around the schools in question,” the statement read.