SYDNEY, Oct. 16 (Xinhua) -- With two earthquakes striking east of New Caledonia at 00:28 GMT on Tuesday, moments later two more also rocked the South Pacific.

After twin 6.5- and 6.3-magnitude tremors hit, the third earthquake measuring 6.6 magnitude struck east of the Loyalty Islands, according to the European-Mediterranean Seismological Centre.

It was initially determined to be at 21.3824 degrees south latitude and 169.3936 degrees east longitude with a depth of 10 km.

The simultaneous fourth earthquake that struck 162 km east of Tardine, was measured at magnitude 6.8 according to the U.S. Geological Survey and was determined to be at 21.4243 degrees south latitude and 169.2646 degrees east longitude, also at a depth of 10 km.

Both tremors hit at 01:03 GMT.

Despite the four earthquakes and a series of other smaller aftershocks, no tsunami warning has been issued for the region.