Officials from Dompu district on Sumbawa island said Thursday's quake damaged 500 homes and small buildings, including mosques and schools, the agency reported.
The homeless were sheltering in tents.
"Based on preliminary reports, we have as many as 504 homes and buildings damaged, and two people are injured," Dompu district chief, Abu Bakar Ahmad, was quoted as saying.
Antara said the quake had its epicentre in the Flores Sea off Sumbawa, a large island that lies to the east of Indonesia's tourist isles of Bali and Lombok. Dompu is around 1,350 km (850 miles) east of Jakarta.
Officials were not available to give more precise details.
Earthquakes frequently hit Indonesia, occasionally causing widespread damage and loss of life.
An earthquake measuring 7.5-7.7 on the Richter scale that struck near Indonesia's Sumatra island in early November killed at least two people and left more than 5,000 people homeless.
- Reuters - Thomson Reuters Foundation
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