GOLDEN, Colorado (October 28, 2012)--A magnitude-7.7 earthquake struck off the coast of western Canada and a tsunami warning has been issued. There are no immediate reports of damage.

The U.S. Geological Survey in Colorado says the quake hit the Queen Charlotte Islands at 11:14 p.m. Saturday local time and was centered 96 miles south of Masset, British Columbia.

The National Weather Service has issued a tsunami warning for coastal areas of British Columbia, southern Alaska, Northern California, Oregon and Washington State.

It said the warning area includes Craig and Sitka, Alaska

The USGS says the 7.7-magnitude quake shook the area and was then followed by a 5.8-magnitude aftershock several minutes later.