They added that more than 130 people had been injured, many with broken bones.
Saturday's quake was the Southeast Asian nation's deadliest since a 2022 quake killed hundreds in West Java.
More than 3,300 people in Indonesia's Sikka region - one of the hardest hit - self-evacuated or were in a sports arena, according to the country's national disaster mitigation agency, known as BNPB.
Some residents were stranded outside collapsed homes under makeshift tents made out of tarpaulin, while others received treatment in a tent outside the local hospital.

Villagers take shelter outdoors following an aftershock from the earthquake in Ende, East Nusa Tenggara, Indonesia, August 17, 2026. Photo: REUTERS/Edgar Su
A sprawling archipelago of 290 million people, Indonesia straddles the "Pacific Ring of Fire", a seismically active zone where tectonic plates meet, triggering frequent earthquakes and volcanic eruptions.
At a now-closed port in Maumere, littered with debris from a collapsed roof and walls, residents told Reuters they were scared of aftershocks.
The disaster agency said on Sunday nearly a thousand aftershocks had been recorded since the quake.
Nearby, hundreds of residents filled a sports stadium, which has been designated as an evacuation spot.

Police officers inspect a heavily-damaged house after an earthquake was felt in Manggarai, East Nusa Tenggara province, Indonesia, August 16, 2026. Photo: REUTERS/Terisno Adon
As the sun was setting, residents stood in line to get warm drinks. Some mothers hooked pieces of clothing to tent frames to form makeshift cradles for their babies. Other children played soccer outside.
One of these mothers was Lisda, 22, who chose to be in a tent with her twin babies due to the fear of sleeping inside her home.
Inside another tent, Yuvienta Saen, 67, recounted her misfortunes. As she felt the quake during her morning prayer, she had to choose between her paralysed husband and herself.
"He told me, you run, I'm handing my fate to God," she said, adding there was a lack of clean water and blankets in the tent.
The area of the quake was hit in 1992 by a magnitude-7.5 earthquake that caused extensive destruction, Indonesia's geophysics agency said.

Debris in a damaged building in the aftermath of an earthquake, at Frans Sales Lega airport in Ruteng, Manggarai regency, East Nusa Tenggara province, Indonesia, August 17, 2026. Photo: REUTERS/Willy Kurniawan
Margaretha Movaldes Da Maga Bapa, head of the region's disaster mitigation agency, said the quake had brought back memories.
"We've had quakes often. But this one really brings back the trauma of the one from 1992," she said, referencing the trucks bringing aid and tents.
Suryaman, a rescue agency official, told Reuters the priority was clearing rubble in the most-affected areas of Manggarai, East Manggarai and Nagekeo to find people possibly still trapped under rubble.
Suryaman said the agency had not received missing person reports but added that landslides and aftershocks were impeding the search.
More than 3,500 military and police officers have been deployed to the region, Cabinet Secretary Teddy Indra Wijaya said in a statement.
Power supply was nearly fully restored, but authorities were still working on fixing distribution lines, state utility firm Perusahaan Listrik Negara said Sunday.
The East Nusa Tenggara government has declared an emergency for the province, BNPB said, a move that allows authorities to mobilise resources and funding.
Reuters
Link nội dung: https://news.tuoitre.vn/thousands-evacuate-after-indonesia-quake-kills-53-aftershocks-hamper-rescue-efforts-10326081710073394.htm