Indonesia evacuated hundreds of tourists from popular resorts and sent rescuers fanning across the holiday island of Lombok Monday after a powerful quake killed at least 91 people and reduced thousands of buildings to rubble.

The shallow 6.9-magnitude quake sparked terror among tourists and locals alike, coming just a week after another deadly tremor surged through Lombok and killed 17 people.

Rescuers on Monday searched for survivors in the rubble of houses, mosques and schools that were destroyed in the latest disaster on Sunday evening.

"There are challenges: the roads were damaged, three bridges were also damaged, some locations are difficult to reach and we don't have enough personnel," said national disaster agency spokesman Sutopo Purwo Nugroho.

An operation was also under way Monday to evacuate some 1,200 tourists from the Gili Islands, three tiny, coral-fringed tropical islands a few kilometres off the northwest coast of Lombok that are particularly popular with backpackers and divers.

Margret Helgadottir, a holidaymaker from Iceland, described people screaming as the roof of her hotel on Gili Air collapsed when the quake struck.

"We just froze, thankfully we were outside," she told AFP tearfully from a harbour in Lombok where she had been evacuated to. "Everything went black, it was terrible."

Footage posted online by Nugroho showed hundreds crowded onto powder-white beaches desperately waiting for transport off the normally paradise Gilis.

"We cannot evacuate all of them all at once because we don't have enough capacity on the boats," Muhammad Faozal, the head of West Nusa Tenggara's tourism agency, told AFP, adding two navy vessels were on their way.

"It's understandable they want to leave the Gilis, they are panicking."

Local disaster officials said 358 tourists had been evacuated so far. At least one person, an Indonesian holidaymaker, was killed on the Gili islands while another tourist died on nearby Bali.

Cover photo: An injured quake victim is stretchered to a makeshift ward set up outside the Moh. Ruslan hospital in Mataram on the Indonesian island of Lombok on August 6, 2018, the morning after a 6.9 magnitude stuck the island.