A strong 6.0 magnitude quake has shaken the Pacific island of Vanuatu, US monitors said on Wednesday, a day after a bigger tremor triggered a small tsunami and sent thousands fleeing for the hills.
The quake hit at 2:35 am (0325 GMT) at a depth of 41 kilometres (25 miles), 75 kilometres west-northwest of Port Vila, the US Geological Survey said.
No tsunami warning was immediately issued.
Tuesday's 7.5-magnitude earthquake shook buildings in the city for about 15 seconds. It did not appear to have caused significant damage, but the resulting minor tsunami triggered panic.