<div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>An investigation into alleged threats made by a teenager against the South Australian public is expanding, with federal police conducting searches at multiple locations linked to the accused.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>The investigation yesterday led to the arrest of an 18-year-old. </span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"Probably the most complex and significant case I've ever received a briefing on," Premier Peter Malinauskas said.</span></div></div><div><div id="adspot-mobile-medium"></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><strong><span>READ MORE:</span></strong><span> </span><a href="https://www.9news.com.au/national/roberts-smith-loses-appeal-against-war-crimes-claims/407ea267-3d8a-46c1-aea5-361f5a4c8e2c"><strong><span>Ben Roberts-Smith to take war crimes claims to High Court after losing appeal</span></strong></a></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"This was a major investigation, it was technically extremely complicated." </span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>The teenager is accused of sending emails threatening staff and students at Glenunga International High School. </span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>It is also alleged that he threatened to attack Gather Round, the Adelaide Fringe Festival, and the state's Jewish community, unless he was given $23 million in bitcoin and cash. </span></div></div><div><div class="OUTBRAIN" data-reactroot="" data-src="//www.9news.com.au/national/south-australia-investigaiton-teenager-alleged-threats/af49e70d-e42a-411a-a6c5-cc9a500c3728" data-widget-id="AR_5"></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Police have not confirmed whether this or next year's Gather Round was allegedly targeted.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>While the investigation is ongoing, police believe the immediate threat has been contained, and the 18-year-old will remain behind bars until at least December.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><strong><span>READ MORE:</span></strong><span> </span><a href="https://www.9news.com.au/national/government-pushes-for-wage-increase-for-millions-of-workers/3eb5a514-55ca-4820-9781-4515a14ad500"><strong><span>Push for three million workers to get a pay rise above inflation</span></strong></a><strong><span></span></strong></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Parents and students at Glenunga International High School have expressed concern following the revelation of the alleged threats, which included bombing, knife attacks, and the use of a vehicle. </span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"It is very concerning, we want to make sure the kids go to school and come back home safe," parent Rosemary Khilnani said.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>The school issued a letter to parents, expressing gratitude to police for their work in ensuring the safety of the school community. The letter stated that the school would continue to operate as usual.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Security measures remain in place at the school.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><em><span>This article was produced with the assistance of</span></em><span> </span><a href="https://www.9news.com.au/technology/9express/16480c33-636a-461f-9c4f-d0e2522c722a"><em><span>9ExPress</span></em></a><em><span>.</span></em></div></div>