Fiji police have sealed off a complex of goverment building in central Suva reportedly to carry out an arrest.
Media have been denied access to the area but police say the action is an exercise ahead of next month's South Pacific Games.
A court hearing is due this morning when more may be known about the action.
Unconfirmed reports say the vice-president, Ratu Jope Seniloli, will appear as a defence witness in a coup-related case.
Last week, police said they were close to completing a probe of his role in the coup three years ago.
Ratu Jope became president under the coup-front man, George Speight, and proceeded to swear in Speight's failed and illegal administration.
A number of government ministers, MPs, senators and the deputy speaker of parliament are already facing serious charges for their roles in the coup.