A magnitude 7.9 earthquake off Alaska's Kodiak Island prompted a tsunami warning for a large swath of coastal Alaska and Canada's British Columbia, while the remainder of the U.S. West Coast were under tsunami watches.  

The strong earthquake was recorded about 175 miles southeast of Kodiak Island early Tuesday morning.  

A tsunami watch for Hawaii was later canceled. 

The quake was initially registered as a magnitude 8.2, but has since been downgraded.

Warnings from the National Weather Service sent to cellphones in Alaska warned: "Emergency Alert. Tsunami danger on the coast. Go to high ground or move inland."  Kodiak officials warned residents to evacuate if they lived in low-lying areas.

People reported on social media that the quake was felt hundreds of miles away, in Anchorage.

"If you are located in this coastal area, move inland to higher ground," the Anchorage Office of Emergency Management said. "Tsunami warnings mean that a tsunami with significant inundation is possible or is already occurring. Tsunamis are a series of waves dangerous many hours after initial arrival time. The first wave may not be the largest."

Kodiak police posted a video warning of their Facebook page. 

"Based on all available data, a tsunami may have been generated by this earthquake that could be destructive on coastal areas even far from the epicenter," the Pacific Tsunami  Warning Center said.

Police had not received any reports of damage.