The death toll from a devastating 6.9-magnitude earthquake in Indonesia’s Lombok island has risen to at least 321, according to officials.

In a statement issued on Friday, the country’s disaster mitigation agency said that more than 270,000 people had been displaced and 1,033 were hospitalised with injuries due to a series of tremors that struck the island of 3.3 million people in the past two weeks.

Nearly three-quarters of residential structures in North Lombok had been destroyed, Sutopo Nugroho, the agency’s spokesperson, said.

On Thursday, a third strong earthquake in two weeks’ time hit Lombok, a popular tourist destination.

The magnitude-6.2 earthquake followed Sunday’s magnitude-6.9 tremor, which came a week after a magnitude-6.4 quake killed at least 17.

In the statement, Nugroho said that after several days of delays, mobile kitchens have started distributing food and water to thousands of evacuees in the worst-hit areas.

“Aid is being distributed as quickly as possible upon arrival,” he said, adding that hundreds of volunteers were helping.

On Thursday, he posted a video on Twitter which showed the collapse of a supermarket.