Florida shooting suspect, Nikolas Cruz was a member of a white supremacist group and had taken part in military-style training exercises, the rights group Anti-Defamation League said on Thursday.

Jordan Jereb, believed to lead the shadowy Republic of Florida (ROF) group, told ADL that Cruz had been "brought up" by a member of the group and joined its training exercises near Tallahassee, Florida.

Armed with an AR-15 assault rifle, Cruz is charged with killing 17 students and adults at Marjory Stoneman Douglas High School in Parkland, Florida.

Republic of Florida describes itself on its website as a "white civil rights organisation fighting for white identitarian politics". It advocates creating a "white ethnostate" in Florida.

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ADL said the group "borrows paramilitary concepts from the anti-government extremist militia movement".

Jereb told ADL that Republic of Florida had not ordered or supported Cruz's attack on his old high school.

Jereb said Cruz "seemed like just a normal, disenfranchised, young white man".

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