A resident passes by a collapsed building in Lombok island, Indonesia, on Aug. 9, 2018. (Xinhua/Lui Siu Wai)

JAKARTA, Aug. 20 (Xinhua) -- The number of death toll from the multiple powerful quakes in Indonesia's Lombok island has reached 506, the national disaster management agency said on Monday.

A 6.4 magnitude quake rattled the island on July 29 followed by a 7.0 magnitude quake on Aug. 5 and two strong quakes of 6.5 magnitude and 6.9 magnitude on Sunday.

A total of 431,436 people have been forced to flee home and take shelter in makeshift tents as the quakes have devastated 74,361 houses and scores of infrastructure facilities, spokesman of the national disaster management agency Sutopo Purwo Nugroho said.

Indonesia has been frequently stricken by quakes as it is situated on a vulnerable quake-affected zone called "the Pacific Ring of Fire".