The suspect in a Florida school shooting was reportedly a member of a white supremacist group.

A representative of the Republic of Florida organisation told multiple outlets that suspect Nikolas Cruz was a member.

The group supports the establishment of a white ethno-state. Its leader Jordan Jereb told the Associated Press that Mr Cruz had participated in paramilitary drills.

The Southern Poverty Law Centre, which tracks extremists groups, included the Republic of Florida on its “Hate Watch” list. Tallahassee-based WTXL-TV reported last year that the white nationalist group was actively seeking more members and said the group was on the Leon County Sheriff’s Office’s radar.

“I do think civil war is a very real possibility in the next two years,” Mr Jereb told the Tallahassee Democrat, predicting “an open, violent clash involving guns and people stabbing and killing each other”.

Authorities have charged Mr Cruz with 17 counts of murder, and investigators are beginning to piece together information about the suspect.

The FBI confirmed that it had received a tip about an online commenter with the name “nikolas cruz” posting “Im going to be a professional school shooter” in 2017. The bureau ran database checks but could not confirm the poster’s identity.

An online trail left behind by Mr Cruz included some “very disturbing” material, Broward County Sheriff Scott Israel told reporters.