Jitrada Tantiwanichayasuk, who has a history of mental problems, will also face a charge of carrying weapons in public.

The lawsuit, lodged at the South Bangkok Criminal Court, said that on September 9, 2005, Jitrada carried two 15cm-long knives and a 20cm blade to the girl's school in Sathorn, where she stabbed and severely injured four students.

The victims were: Chamanat Arif, 12; Chayamon Trailertsamut, 14; Apinya Boonnam, 14; and Jinjutha Rerksirinukool, 13.

Jitrada had aimed to kill the students in the premeditated attacks, the lawsuit alleged. It said that she was mentally fit to stand trial.

The Court asked Jitrada yesterday if she was prepared to confess to the crime. However, she pleaded not guilty, claiming that she had no intention to kill - and that she had no lawyer to represent her.

Considering the case could carry a severe punishment, the Court assigned a pro-bono lawyer for Jitrada and appointed the next hearing for March 12, 2007.

Jitrada was later taken to the Central Women's Prison in Bang Khen.

After the attacks at St Joseph's, Jitrada found a job at a restaurant in Chatuchak, but was recognised from a police sketch that led to her arrest.

Initially, Jitrada was deemed mentally-disturbed and then treated for nine months at the Galaya Raja Nagarindra Institute until she was mentally stable. This led to public prosecutors filing the lawsuit against her yesterday.