A strong 6.5-magnitude earthquake rattled northern Australia and parts of Indonesia today with residents in Darwin reporting widespread shaking, but there were no immediate reports of damage. <br/><br/>The tremor struck off the coast of eastern Indonesia, US seismologists said, but no tsunami warning was issued. The US Geological Survey said, the undersea quake hit about 278 kilometres east-northeast of Dili in East Timor at a depth of 158 kilometres.<br/>