Damaged roads and bridges, power blackouts and lack of heavy equipment on Saturday hampered Indonesia's rescuers after a 6.2 magnitude earthquake left at least 42 dead and hundreds injured on Sulawesi island.
Operations were focused on about 10 locations in the hardest-hit city of Mamuju, where people are still believed trapped following Friday's night-time quake, said Saidar Rahmanjaya, who heads the local search and rescue agency.
Cargo planes carrying food, tents, blankets and other supplies from Jakarta landed late Friday for distribution in temporary shelters. Still, thousands spent the night in the open fearing aftershocks and a possible tsunami.
National Disaster Mitigation Agency spokesman Raditya Jati said 34 people were killed in Mamuju and nearly 200 hospitalised.
The nearby district of Majene was also ravaged, leaving at least eight dead and more than 630 injured, he said.
At least 300 houses in Majene were damaged and about 15,000 people moved to shelters. Many survivors said that aid has not reached them yet due to damaged roads and disrupted communications.
The quake set off landslides in three locations and blocked a main road connecting Mamuju to Majene. Power and phone lines were down in many areas.
Mamuju, the capital of West Sulawesi province with nearly 75,000 people, was strewn with debris from collapsed buildings. A government office building was almost flattened by the quake and a shopping mall reduced to a crumpled hulk. A large bridge collapsed and patients with drips were lying on folding beds under tarpaulin tents outside one of the damaged hospitals.
Two hospitals in the city were damaged and others overwhelmed.
Two ships headed to the devastated areas from the nearby cities of Makassar and Balikpapan with rescuers and equipment, including excavators.
State-owned firm AirNav Indonesia, which oversees aircraft navigation, said the quake did not cause significant damage to the Mamuju airport runway or control tower.
Indonesian President Joko Widodo said Friday that he instructed his Cabinet ministers and disaster and military officials to coordinate the response.
In a telegram sent by the Vatican on behalf of Pope Francis, the pontiff expressed "heartfelt solidarity with all those affected by this natural disaster".
The pope was praying for "the repose of the deceased, the healing of the injured and the consolation of all who grieve". Francis also offered encouragement to those continuing search and rescue effects, and he invoked "the divine blessings of strength and hope".
Indonesia, home to more than 260 million people, is frequently hit by earthquakes, volcanic eruptions and tsunamis because of its location on the Ring of Fire, an arc of volcanoes and fault lines in the Pacific Basin.
In 2018, a 7.5 magnitude earthquake in Palu on Sulawesi island set off a tsunami and caused soil to collapse in a phenomenon called liquefaction. More than 4000 people died, many of the victims buried when whole neighbourhoods were swallowed in the falling ground.
A massive magnitude 9.1 earthquake off Sumatra island in western Indonesia on Boxing Day 2004 triggered a tsunami that killed 230,000 people in a dozen countries.