A Melbourne aid worker helping Indonesian officials get relief to locals after the deadly Lombok earthquake expects the death toll to triple.
Former policeman and child protection charity founder Glen Hulley says many people are missing and families are sleeping on the streets or in fields after 90 per cent of buildings in the northwest town of Tanjung and surrounding region were flattened on Sunday.
The official death toll is 98.
"We're expecting that to double or triple within the next 24 or 48 hours as we're able to co-ordinate military in and begin searching many of these buildings," Mr Hulley told AAP on Tuesday.
A majority of the people who make up the official death toll are from Tanjung, about five kilometres from the epicentre of Sunday's magnitude-7 earthquake.
Only a small number of buildings there have been picked through by crews searching for survivors.
"Only about five per cent of those buildings have been able to be searched ... the government is preparing for the worst," Mr Hulley added.
He and his Project Karma staff are helping Indonesian officials co-ordinate their response.
The local hospital in Tanjung is now rubble and paramedics are grappling with damaged roads as they try to get the injured to Mataram, in the island's west.
"We've got ambulances constantly coming and going because there's no capacity in Tanjung to be able to provide for the injuries, so they're sending them all to Mataram and even that hospital is completely overrun," Mr Hulley said.
Doctors, paramedics and triage nurses from across the globe are travelling to Lombok to volunteer in Tanjung and assist Indonesian officials as they co-ordinate a response.
Mr Hulley says he has been confronted by destruction at every turn.
"Either homes are completely destroyed or they're damaged beyond repair," he said.
"People are just sleeping out in the streets or in the fields because there is no established evacuation centres yet."
Finding a nearby water source that is safe for drinking and accessible to government trucks to then supply unofficial evacuation centres has taken top priority.
"For the couple of camps that we were able to get to last night, there is no food and no water ... so these people have gone without water now for about 24 hours which is getting to a critical stage," Mr Hulley said.
Drones will be used on Tuesday afternoon to identify the areas worst hit and direct military personnel.