Amnesty International is urging people to write to leaders in Fiji to stop the detention, torture and ill-treament of critics of the interim regime.
The human rights organisation says at least ten politicians, trade unionists, government critics and others have been arbitrarily arrested and subjected to severe beatings and other mistreatment by the Fiji military in the last two weeks.
It's calling on people to write to Fiji's president, interim prime minister and foreign minister to stop such action and allow people to demonstrate peacefully on Friday.
Amnesty International New Zealand's chief executive Patrick Holmes says the latest reported torture and ill-treatment of seven young men by the military on Saturday was sparked by their discussions about the demonstration.
"We believe there is physical intimidation. We're getting stories of people being taken into Queen Elizabeth Barracks and being intimidated and beaten up. When friends have protested, they've been threatened with similar violence and threatened with death in cases."
It also wants people to call for an independent investigation into the reported abuses, and for the suspension of the public emergency regulations.