Fiji police are focussing on two provinces which were hotbeds of rebel activity during the May 2000 coup for a possible backlash against the jailing of the vice president, Ratu Jope Seniloli.
Radio Fiji says the police commissioner, Andrew Hughes, has named these as Speight's home province Tailevu and neighbouring Naitasiri, where there were widespread terror attacks on ethnic Indian farmers and their families.
Mr Hughes says police know "who the trouble makers are because of their track record and extreme beliefs."
He says the groups aren't just Suva-based but are spread out in Tailevu and Naitasiri.
Mr Hughes says "in a democracy people are entitled to their views but no one is entitled to incite people to commit offences for any reasons, political or otherwise."
He says "it's not in Fiji's interest for people to try and take the law into their own hands and direct any anger and emotions at the minority groups."
But Mr Hughes says his public relations teams report that village chiefs and headmen are aware that they should not be deceived by people trying "to invoke emotions based on racial or religious grounds."