Indonesia’s geological agency said the quake had a magnitude of 6.2 and was shallow, with a depth of 12km, and centred on the northwest of the island.
The US Geological Survey measured the aftershock at magnitude 5.9.
Filmed by a local resident, the earthquake took place on Thursday and is the third big quake to hit the island in little over a week.
The footage shows officials and reporters attending an event near a hospital when the quake begins.
People are seen running, screaming and crouching on the ground in response to the tremor.
Thousands have been left homeless on the island and are in desperate need of clean water, food, medicine and shelter.
The official death toll from last weekend’s quake stood at 131 on Wednesday, but a government-run news agency put the figure at 347.