Delphine Herbert says there's been two strong aftershocks since the initial quake - which collapsed buildings and sparked tsunami alerts.
Local media report people are trapped in buildings in the city of Hualien, -- but there's not yet word on any casualties.
Sky News Asia Correspondent Stas Butler says the epicentre of the quake wasn't far from Hualien.
He says authorities there have suspended classes and work in light of the damage.
Japan's tsunami warning for a group of southern islands has been downgraded to a tsunami advisory.