JAKARTA, Indonesia -- A powerful earthquake jolted a 2,000-kilometre swath of Indonesia early Saturday, sending hundreds of panicked residents fleeing to higher ground, but fears of a tsunami did not materialize.

There were no immediate reports of injuries or serious damage from the magnitude-7.7 quake.

The earthquake struck beneath the Banda Sea in the Maluku Islands at 1:58 a.m. Saturday, but its depth of 342 kilometres helped minimize the impact, Indonesian meteorological officials said.

Still, fears of a tsunami - like the 2004 waves that killed more than 130,000 people on the western side of the sprawling archipelago - sparked panic among residents and sent them fleeing from their homes, witnesses said.

The quake was felt in many Maluku cities, on the tourist resort island of Bali, and in towns in East Nusa Tenggara and South Sulawesi provinces, but damage was largely limited to cracks in buildings, said Jusuf, an official at the country's main meteorological agency who uses only one name.

It also was felt in the tiny nation of East Timor, 440 kilometres south of the epicentre.

"We poured into the streets in panic and ran immediately to higher places fearing a tsunami," said Salman Rumalesin, a resident of Bula, a Maluku mining town on Seram island.

The Detikcom news Web site reported that the quake cracked walls of houses and government offices in the town of Masohi.

The U.S. Geological Survey said the quake had a magnitude of 7.7 and was centred about 195 kilometres south of Ambon city in the Malukus, known in Dutch colonial times as the Spice Islands.

Later Saturday, a magnitude-4.8 earthquake, centred about 30 kilometres southwest of Krui on the western coast of Sumatra, jolted parts of South Sumatra province. There were no immediate reports of damage or injuries from the quake, which hit at 8:53 a.m., the meteorological office said.

Indonesia, the world's largest archipelago, is prone to seismic upheaval due to its location atop a volcanically active region known as the Pacific Ring of Fire.

Three months after the Dec. 26, 2004, earthquake and tsunami in Aceh province, another strong quake in the region killed more than 900 people on Nias and smaller surrounding islands.

Ambon is about 2,600 kilometres east of Jakarta.