Three significant quakes were recorded by seismologists today, the first a 6.3 shortly before midday which triggered landslides and sent people fleeing for cover.

It was followed nearly twelve hours later by a late evening quake measuring 6.9 and an aftershock soon after of 5.9 strength according to the US Geological Survey.

The picturesque island is already reeling from two devastating quakes on July 29 and August 5 that killed nearly 500 people and made hundreds of thousands homeless.

There were no immediate reports of casualties or damage from the late evening quakes on an island where many have chosen to sleep in tents in recent weeks because of regular aftershocks.

One local resident said the powerful tremor jolted him awake.

"The earthquake was incredibly strong. Everything was shaking," Agus Salim told AFP.

"We were all sleeping in an evacuation tent. I had just fallen asleep when suddenly it started to shake.... Everyone ran into the street screaming and crying." National disaster agency spokesman Sutopo Purwo Nugroho tweeted that blackouts had hit much of the island after the evening quakes.

"Aftershocks are still happening across Lombok," he tweeted. "It's pitch black.... We are still coordinating with officials on the ground." - Landslides and collapsed buildings - Sutopo Purwo Nugroho had earlier said that the morning quake caused panic but no widespread reports of damage. One person died from a suspected heart attack and there were reports of localised damage.

Landslides were reported in a national park on Mount Rinjani where hundreds of hikers had been briefly trapped after the quake in late July. The park has been closed since then.

Local disaster mitigation agency spokesman Agung Pramuja said several houses and other structures in the district of Sembalun, on the slopes of Mount Rinjani, collapsed on Sunday after being damaged by the previous two quakes.

The structures included checkpoints once used by trekkers climbing the mountain, Pramuja said, adding that the exact number of damaged buildings was still being checked.

Residents said the latest earthquake was felt strongly in East Lombok.

"I was driving to deliver aid to evacuees when suddenly the electricity pole was swaying. I realised it was an earthquake. People started to scream and cry. They all ran to the street," East Lombok resident Agus Salim told AFP.

The tremor was also felt in the island's capital Mataram and on the neighbouring resort island of Bali.

"Everybody ran outside their house. They're all gathering in an open field, still terrified," said Endri Susanto, a children's rights activist in Mataram.

"People are traumatised by the previous earthquakes and aftershocks never seem to stop."

The latest tremor comes two weeks after a shallow 6.9-magnitude quake on August 5 damaged tens of thousands of homes, mosques and businesses across Lombok.

At least 481 people died, and thousands were injured.

The hardest-hit region was in the north of the island, which has suffered hundreds of aftershocks.

A week before that quake, a tremor surged through the island and killed 17.

The August 5 quake left more than 350,000 displaced, with many sleeping under tents or tarpaulins near their ruined homes or in evacuation shelters, while makeshift medical facilities were set up to treat the injured.

Badly damaged roads, particularly in the mountainous north of the island, are a headache for relief agencies trying to distribute aid.

The economic toll of the quake is estimated to be at least five trillion rupiah ($348 million).

Dubbed "The Island of a Thousand Mosques", Muslim-majority Lombok is a less popular destination than its neighbour Bali, the Hindu-majority island that is the backbone of Indonesia's $19.4 billion tourist sector.

But Lombok had been earmarked as one of Indonesian President Joko Widodo's "10 new Balis", with the regional government hoping to develop it into a major destination -- especially in the booming halal tourism sector.

Indonesia sits on the so-called Pacific "Ring of Fire", where tectonic plates collide and many of the world's volcanic eruptions and earthquakes occur.

In 2004 a tsunami triggered by a magnitude 9.3 undersea earthquake off the coast of Sumatra in western Indonesia killed 220,000 people in countries around the Indian Ocean, including 168,000 in Indonesia.