A strong 6.2 magnitude earthquake struck eastern Indonesia on Tuesday, the US Geological Survey said, but there was no tsunami warning or immediate reports of damage.
The offshore tremor struck at a shallow depth of eight kilometres (five miles), about 100 kilometres southeast of Kupang on the Indonesian portion of Timor island, the USGS said.
Witnesses described a powerful jolt that lasted a few seconds.
"I was on the second floor of my office and suddenly everybody ran outside because of the earthquake," said an AFP reporter in Kupang.
"All the chairs were shaking... we were traumatised by all the earthquakes in Lombok."
A string of deadly earthquakes that hit Lombok island this summer killed some 555 people.
Indonesia, one of the most disaster-prone nations on earth, straddles the so-called Pacific "Ring of Fire", where tectonic plates collide and many of the world's volcanic eruptions and earthquakes occur.
In 2004 a tsunami triggered by a magnitude 9.3 undersea earthquake off the coast of Sumatra in western Indonesia killed 220,000 people in countries around the Indian Ocean, including 168,000 Indonesians.