A 6.1-magnitude earthquake struck off Sumatra island in western Indonesia on Monday, shaking homes of panicked residents but causing no casualties or damage.
The quake's epicentre was at sea southwest of Padangsidempuan city in northern Sumatra at a depth of 84 kilometres (52 miles), the United States Geological Survey (USGS) reported.
It occurred around 9:59 pm local time (1459 GMT).
The country's meteorology and geophysics agency said there was no tsunami warning after the tremor but told residents nearest the epicentre to beware of potential aftershocks.
Major Indonesian media outlets carried no immediate reports of damage or injuries but some residents reported their homes shaken.
"The earthquake was quite strong and also long. It was not like the usual ones. This time our house shook strongly," said Dody, a resident of North Tapanuli regency in northern Sumatra who like many Indonesians goes by one name.
Indonesia experiences frequent seismic and volcanic activity due to its position on the Pacific "Ring of Fire", where tectonic plates collide.
On November 21, a 5.6-magnitude quake hit West Java province on Indonesia's main island of Java, killing 602 people.