Casualty numbers are expected to rise, and thousands of buildings in the city of Palu, Central Sulawesi, have collapsed. A tsunami was also triggered by the earthquake, generating waves of up to 3 metres (10 feet) high, according to reports.

Rescue efforts are reportedly underway, but are hampered by a major power cut, and a landslide that has blocked the main road to Palu.

The UN chief has extended his condolences to the families of the victims and to the Government of Indonesia, adding that the United Nations stands ready to support the Government-led ongoing rescue and relief efforts.