A series of major quakes that hit the vicinity of Indonesia's Lombok Island since late July has killed 515 people, according to government figures released Tuesday.

About 80 percent of victims lost their lives in a magnitude 6.9 quake that struck on Aug. 5, while the others died from a July 29 quake and two quakes that occurred Sunday.

In addition, more than 7,000 people were injured and 430,000 displaced, and 73,843 houses have been damaged or destroyed by the four quakes.

National Disaster Mitigation Agency spokesman Sutopo Purwo Nugroho estimated total losses at some 7.7 trillion rupiah (about $528 million), mostly due to damage caused to houses and buildings, followed by infrastructure and production.

Speaking at a press conference, Sutopo said the government had been working to reconstruct and rehabilitate damaged houses and public facilities in the wake of the first two quakes, but Sunday's twin quakes, one of which had a magnitude of 6.9, have hindered those efforts.

"And many houses that were earlier only slightly damaged either collapsed or became seriously damaged," he added.

Due to the quakes, he said, the already water-deficient islands of Lombok and Sumbawa lack access to clean water, a problem compounded by the fact that August and September are the height of the dry season, he said.

President Joko "Jokowi" Widodo has been under mounting pressure to declare a national disaster to speed up efforts for recovery and rehabilitation.

But Sutopo said that would be unnecessary "because we have mitigated the disaster at a national-scale level."

The spokesman added that Indonesia does not require assistance from foreign countries, noting, "Even a country like Japan that has experienced a lot of earthquakes only requested international assistance once, after having been hit by the earthquake and tsunami in northeastern Japan in 2011."

Indonesia sits in one of the most active seismic regions in the world, the Pacific Ring of Fire -- an area in which a large number of earthquakes and volcanic eruptions occur.