WELLINGTON, New Zealand — A strong earthquake has struck near the South Pacific nation of Vanuatu, but police say were no immediate reports of injury or damage.

The magnitude 6.3-quake struck at 5:35 a.m. Wednesday was centered 45 miles north of Port Vila, the U.S. Geological Survey reported on its web site.

No tsunami warning was issued by the Hawai'i-based Pacific Tsunami Warning Center.

Vanuatu is part of the Pacific "ring of fire" — an arc of earthquake and volcanic zones stretching from Chile in South America through Alaska and down through Vanuatu to Tonga in the South Pacific.

A chain of 83 islands, it lies just over 1,400 miles northeast of Sydney, Australia.