Mass burials have begun in Indonesia after the country was hit by a powerful tsunami triggered by a 7.5 magnitude earthquake, killing at least 844 people.

The death toll is expected to rise as rescuers reach coastal areas that were cut off by the quake.

Search and rescue teams are yet to fully assess the situation in the towns of Donggala, Sigi and Parigi Moutong.

Some 1.2 million people live across the three areas.

A mass grave, measuring 10m by 100m, has been dug in the hard-hit city of Palu, the capital of Indonesia’s central Sulawesi province.

According to Tiopan Aritonang, a local army commander, 545 bodies will be brought to the grave from one hospital alone, and 18 burials have already taken place.

All the victims coming from local hospitals have been photographed, so that families can locate where their loved ones have been buried.

Mass burials begin in Palu (AP)

The area, next to a public cemetery, can hold 1,000 bodies, said local military spokesman Mohammad Thorir.

“This must be done as soon as possible for health and religious reasons,” said Willem Rampangilei, chief of Indonesia‘s National Disaster Mitigation Agency.

The majority of Indonesia’s population is Muslim and religious custom calls for burials soon after death, traditionally within 24 hours.

Video footage showed residents walking between body bags and checking to see if they could identify faces.

Residents survey a wrecked area (AP ) (AP)

Survivors in Palu are becoming increasingly desperate as food and supplies in the area run low.

Local television said around 3,000 people rushed to Palu airport and attempted to leave the city.

Some residents were filmed screaming in anger after they were unable to board departing military planes.

Only a few commercial flights are leaving from the airport.

“We have not eaten for three days!” one woman yelled. “We just want to be safe!”

Nearly 50,000 people have been displaced by the quake in Palu alone.

The city is home to 380,000 residents.

Indonesia quake and tsunami in pictures Show all 17 1 /17 Indonesia quake and tsunami in pictures Indonesia quake and tsunami in pictures A handout photo made available by the Indonesian National Board for Disaster Management (BNPB) shows an aerial image of Palu city harbor in Palu, central Sulawesi, Indonesia, 29 September 2018 after a 7.7 magnitude earthquake and tsunami hit Palu, central Sulawesi, Indonesia, 28 September 2018. According to BNPB the death toll from the Sulawesi earthquake and tsunami has jumped to 384 as the number might be keep rising EPA Indonesia quake and tsunami in pictures A handout photo made available by the Indonesian National Board for Disaster Management (BNPB) shows an aerial image of the coastal area of Palu city, central Sulawesi, Indonesia, 29 September 2018 after a 7.7 magnitude earthquake and tsunami hit Palu, central Sulawesi, Indonesia, 28 September 2018. According to BNPB the death toll from the Sulawesi earthquake and tsunami has jumped to 384 as the number might be keep rising. EPA Indonesia quake and tsunami in pictures A handout photo made available by the Indonesian National Board for Disaster Management (BNPB) shows an aerial image of the coastal area of Palu city, central Sulawesi, Indonesia, 29 September 2018 after a 7.7 magnitude earthquake and tsunami hit Palu, central Sulawesi, Indonesia, 28 September 2018. According to BNPB the death toll from the Sulawesi earthquake and tsunami has jumped to 384 as the number might be keep rising. EPA Indonesia quake and tsunami in pictures A man surveys the damage caused by earthquake and tsunami in Palu, Central Sulawesi, Indonesia, Saturday, Sept. 29, 2018. The powerful earthquake rocked the Indonesian island of Sulawesi on Friday, triggering a 3-meter-tall (10-foot-tall) tsunami that an official said swept away houses in at least two cities. AP Indonesia quake and tsunami in pictures A mosque is seen heavily damaged by earthquake and tsunami in Palu, Central Sulawesi, Indonesia, Saturday, Sept. 29, 2018. The powerful earthquake rocked the Indonesian island of Sulawesi on Friday, triggering a 3-meter-tall (10-foot-tall) tsunami that an official said swept away houses in at least two cities. AP Indonesia quake and tsunami in pictures A department store building is seen heavily damaged by earthquake in Palu, Central Sulawesi, Indonesia, Saturday, Sept. 29, 2018. The powerful earthquake rocked the Indonesian island of Sulawesi on Friday, triggering a 3-meter-tall (10-foot-tall) tsunami that an official said swept away houses in at least two cities. AP Indonesia quake and tsunami in pictures Indonesian soldiers load emergency supplies into a Hercules military plane before heading to Palu at Halim Perdanakusuma military base in Jakarta, Indonesia, Reuters Indonesia quake and tsunami in pictures The ruin of a mosque badly damaged by earthquake and tsunami is seen in Palu, Central Sulawesi, Indonesia, Saturday, Sept. 29, 2018. The powerful earthquake rocked the Indonesian island of Sulawesi on Friday, triggering a 3-meter-tall (10-foot-tall) tsunami that an official said swept away houses in at least two cities. AP Indonesia quake and tsunami in pictures A handout photo made available by the Indonesian National Board for Disaster Management (BNPB) shows the collapsed Anutapura hospital after a 7.7 magnitude earthquake in Palu, Central Sulawesi, Indonesia, 28 September 2018 (issued 29 September 2018). According to BNPB, a series of powerful earthquakes hit Central Sulawesi killing at least one person and injuring dozens. EPA Indonesia quake and tsunami in pictures People walk near the ruins of a shop at the beach after a tsunami hit in Palu, Indonesia Sulawesi Island, Reuters Indonesia quake and tsunami in pictures The ruins of cars as seen after tsunami hit in Palu, Indonesia Reuters Indonesia quake and tsunami in pictures Residents make their way along a street full of debris after an earthquake and tsunami hit Palu, on Sulawesi island on September 29, 2018. - Rescuers scrambled to reach tsunami-hit central Indonesia and assess the damage after a strong quake brought down several buildings and sent locals fleeing their homes for higher ground. AFP/Getty Images Indonesia quake and tsunami in pictures A handout photo made available by the Indonesian National Board for Disaster Management (BNPB) shows houses in ruins after a 7.7 magnitude earthquake in Palu, Central Sulawesi, Indonesia, 28 September 2018 (issued 29 September 2018). According to BNPB, a series of powerful earthquakes hit Central Sulawesi killing at least one person and injuring dozens EPA Indonesia quake and tsunami in pictures A shopping center heavily damaged following an earthquake in Palu, Central Sulawesi, Indonesia September Reuters Indonesia quake and tsunami in pictures A handout photo made available by the Indonesian National Board for Disaster Management (BNPB) shows houses in ruins after a 7.7 magnitude earthquake in Palu, Central Sulawesi, Indonesia, 29 September 2018. According to BNPB, a series of powerful earthquakes hit Central Sulawesi killing at least one person and injuring dozens. EPA Indonesia quake and tsunami in pictures Residents trying to salvage belongings from their homes which collapsed after an earthquake and tsunami hit Palu on Sulawesi island on September 29, 2018. - Nearly 400 people were killed when a powerful quake sent a tsunami barrelling into the Indonesian island of Sulawesi, officials said on September 29, as hospitals struggled to cope with hundreds of injured and rescuers scrambled to reach the stricken region AFP/Getty Indonesia quake and tsunami in pictures Medical team members help patients outside a hospital after an earthquake and a tsunami hit Palu, on Sulawesi island on September 29, 2018. - Rescuers scrambled to reach tsunami-hit central Indonesia and assess the damage after a strong quake brought down several buildings and sent locals fleeing their homes for higher ground AFP/Getty

“We will send food today, as much as possible with several aircraft,” said disaster agency spokesman Sutopo Purwo Nugroho, adding that generators, heavy equipment and tents were also needed.

Palu’s streets are strewn with debris from fallen buildings, including from a damaged mosque, a collapsed bridge and a shopping complex.

In the Petobo area of the city, the quake caused liquefaction, when loose, water-filled soil near the surface loses its strength, causing massive damage.

“In Petobo, it is estimated that there are still hundreds of victims buried in mud material,” Mr Nugroho said.

Residents, who pulled loved ones both alive and dead from the rubble, expressed frustration over the fact that rescuers only arrived in the area on Monday.

“Up to Saturday we still saw many people screaming for help from the roofs,” said 52-year-old Idrus.

“But we could not do anything to help them. Now their cries are no longer heard.”

Many people are also believed to be trapped under destroyed houses in the Balaroa area of Palu.

Hundreds have been injured and hospitals in the city have been overwhelmed with patients.

Indonesia is vulnerable to earthquakes due to its location in the Ring of Fire, an arc of fault lines and volcanoes across the Pacific Basin.

In December 2004, an earthquake off Sumatra island in western Indonesia triggered a tsunami that killed 230,000 people in a dozen countries.