Indonesia is still recovering from a 6.1-magnitude quake that killed 30 people and injured 275 others three days ago.
In the last earthquake, the death and destruction were mainly in the province of Aceh on the island of Sumatra.
Indonesia is on the Ring of Fire, an arc of fault lines circling the Pacific Basin that is prone to frequent earthquakes and volcanic eruptions.
In 2004, a 9.1-magnitude underwater earthquake off the coast of Sumatra triggered a tsunami that killed more than 200,000 people in 14 countries. The majority of the deaths were in Indonesia, with Aceh bearing the brunt.