(Updates throughout with details)
By Steve Quinn
JUNEAU, Alaska July 25 (Reuters) - An earthquake with a magnitude of 5.9 struck the coast of Alaska early on Friday, shaking people awake in the capital Juneau and cutting off some communications in the southeast part of the state, officials said.
An underwater fiber cable linking the area with the rest of the state was damaged, knocking out service for an unknown number of Internet and telephone users, said a spokeswoman for Alaska Communications.
Police said there were no immediate reports of damage, but the quake was felt throughout several coastal communities.
The National Earthquake Information Center, which is part of the U.S. Geological Survey (USGS), said it was the strongest of 12 quakes to hit the region during a five-hour period.
"The larger the magnitude, the longer it can go on," said a geophysicist at the center, Paul Caruso. "We got a lot of reports that it was felt."
The earthquake struck at 2:54 a.m. local time about 97 miles (156 km) west of Juneau. The USGS said its epicenter was 10 km, or 6 miles, deep.
Reports of communications outages began trickling in throughout the morning and early afternoon, said Hannah Blankenship of Alaska Communications.
"Right now, we are working to identify which areas and how many people are affected," she said. "We know some do have wireless, voice and data service but others do not." (Additional reporting by Carey Gillam in Kansas City; Editing by John Stonestreet and Susan Heavey; Editing by Ron Popeski)