Around 5,000 people have been evacuated after a magnitude-7.7 earthquake smashed an area in eastern Indonesia, killing at least ​51, blocking roads and causing landslides, authorities said on Sunday.

Thirty-six people were seriously ‌injured in the Saturday morning quake in East Nusa Tenggara province, while 77 had minor injuries, Deputy Health Minister Benjamin Paulus Octavianus told a televised meeting.

The quake, followed by some 341 aftershocks, is the ​Southeast Asian nation's deadliest since a 2022 quake killed hundreds in West Java.

More than 3,300 ​people in the Sikka region self-evacuated or were in a sports arena, ⁠said the disaster mitigation agency BNPB.

Some Sikka residents were stranded outside collapsed homes under a ​makeshift tent made out of tarp, while some people received treatment in a tent outside ​a hospital in the port town of Maumere.

"I only brought my body," Abdul Mutas, 63, told Reuters after he and his family slept on a tarp surrounded by trees in the town of Sikka. "The tides ​were rising, so we ran," he said, describing their reaction to the quake.

"Almost all of ​Sikka's residents didn't dare stay indoors, so they slept on a porch or a tent outside," Simon ‌Subandi, ⁠deputy regent of Sikka, told news channel KompasTV.

More than 3,500 military and police officers have been deployed to the region, Cabinet Secretary Teddy Indra Wijaya said in a statement.

Rescuers reached parts of Maumere that had been blocked by landslides, Indonesia's search and rescue agency said. There ​was no immediate count ​of those missing, but ⁠most of them were trapped under rubble, and more than 1,300 homes were damaged, BNPB said.

Twenty petrol stations were not operational due ​to power outages, said state energy firm Pertamina.

The East Nusa Tenggara government ​is considering ⁠declaring an emergency for the province, BNPB said, which would allow authorities to mobilise resources and funding.

The area of the quake was hit in 1992 by a magnitude-7.5 earthquake that caused extensive ⁠destruction, ​Indonesia's geophysics agency said.

Indonesia, a sprawling archipelago of 290 ​million people, straddles the "Pacific Ring of Fire", a seismically active zone where tectonic plates meet, triggering frequent earthquakes and ​volcanic eruptions.