There were no immediate reports of damage or casualties.


The magnitude 5.8 earthquake struck near southern Aceh's Singkil town and its surrounding areas at 11.30am (0430 GMT), said Muslih, an official at the Meteorology and Geophysics Agency, on Saturday.


Muslih said the quake strongly jolted Singkil, but so far there were no reports of its effects.


Andayani, an official at the local district office, said many panicked city-dwellers ran out of their houses when the quake struck.


"Thank God, we have not heard of any damage or casualties

so far," Andayani said.


The private El Shinta radio reported that the quake also jolted Nias island in North Sumatra province, also causing panic among villagers.


Seismic upheaval


Indonesia, the world's largest archipelago, is prone to seismic upheaval due to its location on the so-called Pacific Ring of Fire, an arc of volcanoes and fault lines encircling the Pacific Basin.


The devastated region's residents 
remain on edge about tremors

Aceh, on the northern tip of Sumatra Island, was the hardest hit by the 26 December magnitude 9 quake and subsequent tsunami that killed more than 176,000 people in 11 countries, 131,000 of them in Aceh alone.


Three months later ,another strong tremor killed more than 900 on Nias and smaller surrounding islands, also in western Indonesia.


Earthquakes of magnitude 6 and below are not considered strong enough to trigger a tsunami.

Source: Agencies