A 6.1-magnitude earthquake struck off Indonesia's main island of Java on Saturday, the US Geological Survey reported, flattening homes and sending panicked residents running onto the street.

Dozens of buildings were damaged, including 16 houses and that collapsed in the town of Banyumas, as well as a mosque that crumbled, National Disaster Mitigation Agency spokesman Sutopo Purwo Nugroho said.

"Authorities are continuing to asses other buildings for damage," he said.

"So far there are no reports of casualties."

People in the town of Adipala near the epicentre said they felt the ground shaking hard for up to 20 seconds, as the quake struck in the sea off the coast of southern Java.

"We all just ran onto the street, there were so many people," Astri, a florist who goes by one name, told AFP by phone from her flower shop.

"But it doesn't seem to have damaged anything around here, and we're getting back to work," she said.

The quake struck 39 kilometres (24 miles) south-southeast of Adipala, according to the USGS. It was felt in several towns up to 50 kilometres from the Javanese coast, including in the more densely populated Yogyakarta city, where at least eight homes were damaged, Nugroho said.

The quake hit at 12:14 pm (0514 GMT) at a depth of 83 kilometres, and Indonesia's meteorology, climatology and geophysics agency said there was no risk of a tsunami.

Indonesia sits on the Pacific "Ring of Fire", where tectonic plates collide, causing frequent seismic and volcanic activity.

A 6.1-magnitude quake that struck Aceh province on Sumatra island in July 2013 killed at least 35 people and left thousands homeless.

'Strong' 5.8-magnitude quake rattles Greek island of Cephalonia
Athens (AFP) Jan 26, 2014 - A 5.8-magnitude earthquake struck the Greek island of Cephalonia in the Ionian Sea on Sunday, the Athens Observatory said, but there were no immediate reports of injuries.

The quake took place at 15:55 pm (1355 GMT) and was described as "very strong" by the Observatory. Its epicentre was 6 kilometres (3 miles) from the island's main town of Argostoli, some 280 km west of Athens.

"For the moment no casualties have been reported," a local police official told AFP. Early indications suggested there had been some damage to roads, he added.

"Some rocks have fallen onto roads and the roofs of some old houses have been damaged," the spokesman for the fire brigade, Nikos Tsongas, told local radio.

There were also reports that shop windows had been broken in Argostoli.

The tremor brought nervous residents into the streets, according to local authorities.

The quake was felt on several Ionian islands and as far away as Athens.

Several smaller aftershocks have been recorded.

Greek Prime Minister Antonis Samaras has asked Interior Minister Yiannis Mihelakis to pay a visit to the island, ANA news agency reported.

Greece is one of Europe's most earthquake-prone countries.

Cephalonia has previously been struck on several occasions and in August 1953 virtually every house on the island was destroyed during a major earthquake.

The island was also the setting for the popular novel Captain Corelli's Mandolin, about a Second World War romance between an Italian soldier and a local woman. A 2001 movie of the same name, starring Nicolas Cage and Penelope Cruz, was filmed on the island.