At least 832 people were killed in the devastating earthquake and tsunami that hit the Indonesian island of Sulawesi, the national disaster agency says.

Many people were reported trapped in the rubble of buildings that collapsed in Friday’s 7.5-magnitude earthquake, agency spokesman Sutopo Purwo Nugroho told a news conference.

The quake triggered tsunami waves as high as 6m (20ft), he added.

Vice-President Jusuf Kalla said the final death toll could be thousands.

Rescuers have been digging by hand in the search for survivors in the city of Palu.

“What we now desperately need is heavy machinery to clear the rubble. I have my staff on the ground, but it’s impossible just to rely on their strength alone to clear this,” Muhammad Syaugi, head of the national search-and-rescue agency, told AFP news agency.

There have also been concerns about the town of Donggala, where the impact is still unclear.