GEORGETOWN, Guyana (AP) — A teenage student who police in Guyana accuse of deliberately setting a fire in a girl’s dormitory that killed 18 schoolmates and a five-year-old boy was charged Monday as an adult with 19 counts of murder.

The 15-year-old girl appeared virtually at the hearing in a court south of the capital, Georgetown, and was ordered held in custody pending further court proceedings.

Investigators allege she ignited the blaze at Mahdia Secondary School on May 21 in anger with the administrator over the confiscation of her mobile telephone. The government boarding school serves remote Indigenous villages in the country’s southwest.

The defendant was not allowed to plead to the charges and will make a second court appearance on July 5 when state and defense attorneys will indicate if they are ready to start a preliminary trial. If found guilty, the defendant could face life in prison.

The fire at the school began shortly before midnight. More than two dozen students were injured while rescuers pulled at least 20 others from the heavily iron-grilled building. One of the critically injured students has been flown to a New York hospital for specialist treatment, while most have been discharged.

All five doors were locked with keys from inside.

National Security Advisor Gerald Gouveia has said that the dorm administrator, or house mother, locked all the doors to prevent the female students aged 12-18 from sneaking out to socialize in the mining town with adult males. She panicked and fumbled with the keys as the blaze raced through the building.