Axel Rudakubana, 18, the suspect accused of killing three young girls in the deadly Southport mass stabbing attack, has received additional charges of producing the poison ricin and possessing an al-Qaeda military training manual, the BBC reported.

The additional charges are in addition to the three counts of murder, ten counts of attempted murder, and possession of a knife that Rudakubana was charged with in August following a mass stabbing during a Taylor Swift-themed dance class in Southport on July 29. He allegedly killed Bebe King, 6, Elsie Dot Stancombe, 7, and Alice da Silva Aguiar, 9, and injured ten others, including two adults and eight children.

Authorities said Rudakubana will appear in Westminster Magistrates' Court on Wednesday.

Merseyside Police Chief Constable Serena Kennedy told reporters during a press brief Tuesday that Rudakubana has been charged with the production of a biological toxin in violation of section one of the Biological Weapons Act 1974, and possessing a PDF document likely to be used by someone wanting to commit or prepare an act of terrorism, which violates section 58 of the Terrorism Act 2000.

Counter-terrorism police have not declared the incident a terrorism incident and need to determine a motive to place an official terrorism charge. Chief Kennedy said the investigation remains ongoing, explaining that investigators allegedly located ricin, a deadly poison, and the al-Qaeda training manual at Rudakubana's home in the Lancashire village of Banks. The poison was not discovered at the scene of the stabbing attack, police said.

The mass stabbing attack provoked nationwide unrest after it was learned that Rudakubana comes from a Muslim African immigrant family. This prompted white working-class people to oppose the UK's mass migration policies. The protests devolved into riots, and Muslim migrants organized "Muslim armies" to patrol the streets, engaging in physical attacks on white protesters. Following the turmoil, white demonstrators were convicted to up to ten years in prison, and social media was utilized to crack down on free expression.

The trial is expected to begin in July, per court documents.