A 16-year-old boy from northwest England has been charged with trying to obtain a biological toxin.

Greater Manchester Police said Wednesday that the boy, whose name was not released because of his age, had been charged with "attempting to acquire a biological toxin or agent." It did not identify the substance.

The boy is due to appear in a youth court on Thursday.

He was arrested In the Manchester area on Monday on suspicion of involvement in terrorism. A 16-year-old girl arrested with him was released Wednesday without charge.

Police have said the investigation is not linked to an international terrorist plot.

The charge comes a day after a 31-year-old man from Liverpool in northwest England appeared in court on a charge of trying to purchase the deadly toxin ricin.