The Tongan Government says continued threats from some in the pro-democracy movement have prompted it to maintain a limited state of emergency in the capital for an 18th month.
The emergency was first declared in November 2006 after rioters wrecked much of the centre of Nuku'alofa.
The emergency regulations control activity in a zone in the capital and restrict meetings to no more than five people.
The Information Minister, Afu'alo Matoto, says police fear further civil disturbance caused by democracy advocates.
"They are saying that if the Government does not enact changes - political reform to be effective this year, there will be further disturbances. The main recommendation of course comes from the police, because they don't know if these threats can be carried out or not."
Afu'alo Matoto says the emergency will continue for at least another month and possibly beyond the King's coronation in August.
One election candidate has claimed the regulations are an attempt by the government to hinder its political opponents.