At least 384 people were killed after a major earthquake and a tsunami hit the city of Palu on Indonesia’s Sulawesi island on Friday, Reuters reported, citing the disaster mitigation agency officials. At least 540 people were injured and 29 were reported missing.

Strong aftershocks continued to rock the city on Saturday morning after waves of up to two metres high swept through it triggered by a 7.5 magnitude earthquake on land.

National Disaster Mitigation Agency spokesperson Sutopo Purwo Nugroho said many of those who died were swept away in the tsunami. “When the [tsunami] threat arose yesterday [Friday], people were still doing their activities on the beach and did not immediately run and they became victims,” Nugroho said, adding that some people climbed 18-feet-high trees to escape the tsunami and survived.

Nugroho described the damage as “extensive” with thousands of houses, hospitals, shopping malls and hotels collapsed, a bridge washed away and the main highway to Palu blocked due to a landslide.

“Bodies of victims were found in several places, because they were hit by the rubble of collapsing buildings or swept away by the tsunami...but we are still collecting data,” Nugroho had said earlier.

Indonesia’s meteorological and geophysics agency BMKG issued a tsunami warning after the earthquake, but lifted it 34 minutes later.

The epicentre of the quake was closest to Donggala, a city of about 2.7 lakh people, and the tsunami hit both Donggala and the nearby Palu, which has over 3 lakh residents, reported The Sydney Morning Herald. Palu is the capital of Central Sulawesi province.

Around 16,700 people were evacuated to 24 centres in Palu. The airport at Palu has been closed until Saturday evening. The earthquake and tsunami also caused a power outage, cutting communications around Palu.

Chief security minister Wiranto said the military had started sending in cargo planes from the capital Jakarta carrying relief aid.

Red Cross volunteers have left for the affected areas, the organisation said in a statement. “We are now getting limited communications about the destruction in Palu city, but we have heard nothing from Donggala and this is extremely worrying,” said its chief Jan Gelfand. “There are more than 3,00,000 people living there.”

Indonesian President Joko Widodo tweeted on Friday that he was monitoring the development and his staff were on alert to “deal with all possibilities after the quakes”. He is scheduled to visit evacuation centers in Palu on Sunday.

On Friday, another earthquake, of 6.1 magnitude, killed one person and injured 10 people. A few houses were also damaged, according to authorities.

A series of earthquakes in July and August killed nearly 500 people on the holiday island of Lombok, hundreds of kilometres southwest of Sulawesi.