A strong 6.6 magnitude earthquake has struck in Papua New Guinea early this morning, but no tsunami warning has been issued.

The United State Geological Survey said the quake struck near the island of New Britain at a depth of 22km, at 4.04am NZT.

The Pacific Tsunami Warning Centre reported there is no threat of a widespread destructive tsunami, however strong earthquakes can generate smaller waves that can cause damage.

- NZ Herald staff