Authorities say a strong earthquake has hit off the coast of the Northern Mariana Islands near Saipan in the northwestern Pacific Ocean.

The U.S. Geological Survey says the magnitude-7.7 earthquake struck Friday at a depth of 117 miles (188 kilometers). The Pacific Tsunami Warning Center says there's no threat of a destructive Pacific tsunami and no danger to Hawaii, Alaska or the West Coast of the U.S.

There are no initial reports of damage or injuries on the Northern Mariana Islands, a commonwealth of the U.S. Saipan is the capital and the largest island in the archipelago.