SYDNEY/MELBOURNE, Sept 22 (Reuters) - An earthquake of magnitude 6.0 struck near Melbourne in Australia on Wednesday, Geoscience Australia said on Wednesday. The quake"s epicentre was near the rural town of Mansfield, about 200 kilometres (124 miles) northeast of Melbourne, and was at a depth of 10 km (6 miles). Radio station 3AW posted a picture of rubble on a street in Melbourne which it attributed to the quake, and people in northern parts of the city said on social media they had lost power. No tsunami threat has been issued to the Australian mainland, islands or territories, the country"s Bureau of Meteorology said in a statement.