The US Geological Survey said a magnitude 6 earthquake has shaken Vanuatu _ a day after a stronger quake off the South Pacific island nation generated a small tsunami. The Wednesday quake was too small to cause a tsunami and there were no immediate reports of injuries or damage. A statement said the quake's epicenter was 46 miles (73 kilometers) northwest of the capital Port Vila and 25 miles (41 kilometers) deep. A powerful 7.5 magnitude quake off Vanuatu on Tuesday generated a small tsunami, shook buildings and brought down power lines. There was no major damage or serious injuries, AP reported.