Apparently, the region (particularly Lombok) has experienced numerous quakes since July.
(CNN) Earthquakes struck near two popular vacation destinations Sunday, one rattling the South Pacific islands of Fiji and Tonga, and another striking Indonesia’s Lombok.Lombok earthquake death toll surges above 400. The quake roughly 200 miles off both Fiji and Tonga measured a massive 8.2-magnitude but was hundreds of miles deep.
Source: Major earthquakes strike near Fiji and in Indonesia’s Lombok island – CNN