Four government vehicles have been set on fire outside the tax and customs department in Tonga.
Firefighters have extinguished the blaze which started at 3am local time.
Police say they've made no arrests in connection with the incident.
Government officials toured the scene soon after the fire, whilst it was still dark in Tonga.
The incident is not being officially linked with ongoing strike action by civil servants.
Mateni Tapueluelu from Nuku'alofa.
"It is sad that this morning that a lot of people will put this fire in the context of the strike that is taking place right now with the civil servants. Yesterday the students of Atele college, sometimes known as Tonga college, smashed down their administration office. They also passed on a letter to be read during the rally, and said they will burn down a hundred houses in Tonga in support of the strike."