Fiji police say they are unclear of the motivation behind the threats which forced the Prime Minister to evacuate his Suva office twice yesterday.
A police spokesperson, Mesake Koroi, says that Mr Qarase, senior officials, several other ministers and hundreds of public servants had to leave their offices when police received two bomb threats.
Bomb disposal teams found nothing.
Mr Koroi says the police have no idea who is behind the hoax calls or what the motive is.
"We believe that it is just some people are up to no good and they're just trying to destabilise what little semblance of sanity that we have."
During the weekend central Lautoka was disrupted when another hoax forced the evacuation of the city's largest hypermarket as thousands of shoppers and tourists from a visiting cruise ship were inside.