Watch: 1200 tourists evacuated from Indonesia's Gili island after earthquake kills 91 people

After a powerful earthquake struck Indonesia's Lombok island killing at least 91 people, around 1200 tourists were being evacuated from Indonesia's tiny Gili islands on Monday.

The Gilis are three coral-fringed tropical islands popular with backpackers and divers, a few kilometres off the northwest coast of the larger Lombok island.

National disaster agency spokesman Sutopo Purwo Nugroho told reporters some 200 "domestic and foreign" tourists had already been taken off the islands.

"There are 700 more tourists still waiting to be evacuated," he added. 

Last night a strong earthquake has struck the Indonesian tourist island of Lombok, killing at least 91 people and shaking neighbouring Bali, one of Southeast Asia's leading tourist destinations.

The seven-magnitude tremor struck 10 kilometres (six miles) underground, according to the US Geological Survey.

It was followed by two light to moderate secondary quakes and nearly two dozen aftershocks.

The powerful earthquake and strong aftershocks rocked Bali and Lombok island of Indonesia, causing thousands of people to rush out of their homes and take outdoor shelters.

The quake, which was 31 kilometres (19 miles) deep and near Loloan on the north end of Lombok, also triggered a brief tsunami warning.

The tremor was also felt in Bali to the west.

Most of the victims died in northern Lombok, informed Haji Rum, head of the West Nusa Tenggara Disaster Management Agency.