Jakarta - A 5.9-magnitude earthquake struck the southern part of Indonesia's Java Island early Thursday, but there were no immediate reports of injuries or damage, an official said.

The tremblor occurred about 3:31 a.m. (2031 GMT Wednesday) and was centred in the Indonesian Ocean, 147 kilometres southeast of Sukabumi district in West Java, said Aprilyanto, an official at the Meteorology and Geophysics Agency in Jakarta.

The quake struck at a depth of 59 kilometres beneath the seabed, he said, and was felt along a wide stretch of the southern coast of West Java, but there were no reports of injuries or damage.

Indonesia, the world's largest archipelago nation, is prone to earthquakes because the country sits on Asia's so-called 'Ring of Fire' where continental plates collided and earthquakes and volcanic eruptions are common.