Sweden’s security service has warned an extremist network has been meeting at a school and says children are at risk of radicalisation. It comes weeks after another school was shut down after it was revealed its staff had included former ISIS fighters. In a statement to the School Inspectorate, seen by Swedish radio station P4 Gävleborg, Sweden’s security services Sapo said the students were at risk of being "subjected to radicalisation and recruitment to violent environments" at the Nya Kastet's school in Gävle. The statement revealed that an extremist network had held meetings in the school premises and that the imam of a mosque in Gävle, Gävleimamen Riyad Abdulkarim Jassim, also known as Abo Raad, had a significant influence on the school's activities. The Nya Kastet, which was formed in 2015, failed a school inspection last year and the police have been investigating after funds worth €2.8 million (Dh 11.4 million) disappeared. Anders Gullberg, investigator at the School Inspectorate, has said the information is "serious" and needs "careful investigation". Jassim was one of five top Muslim clerics arrested in May in a series of raids linked to suspected extremism in Sweden. Also arrested were his son Hussein Al-Jibury, an imam of a mosque in Umeå, Fekri Hamad, imam of a mosque in Västerås, and the chief executive of the Vetenskapsskolan School in Gothenburg,<strong> </strong>Abdel-Nasser El Nadi. In August, Sweden's Migration Tribunal ruled that all the men should be deported over fears they pose a threat to national security. Two weeks ago the Vetenskapsskolan School was shutdown amid fears students were at risk of being radicalised. “We have made an assessment that the new owner does not take a completely independent position with the previous owner,” said the school inspectorate’s lawyer, Johan Kylenfelt. It was claimed that one member of the school’s new board had shared ISIS propaganda online. “Because there are links to previous owners who are deemed to be a threat to the security of the state, the Swedish School Inspectorate assesses that there is a serious risk to the school’s students,” he added. Reports claim four former ISIS fighters have taught in the school, along with another man who has been accused of soliciting funds for terrorism. Over the past few years, the extremist movements in Sweden have seen a significant growth and the number of individuals affiliated with violence-promoting extremism has risen from a few hundred to several thousand.