ANCHORAGE, Alaska -- A strong earthquake has shaken southeastern Alaska, but officials say there is no danger of a tsunami and there are no immediate reports of damage.

The U.S. Geological Survey says the magnitude 6.0 quake struck about 1 a.m. Thursday and was centred in the ocean, about 320 kilometres south of the capital, Juneau.

The quake was widely felt across the region, according to the Alaska Earthquake Information Center. But it had no immediate reports of any damage.

The centre says the quake is an aftershock to a magnitude 7.5 temblor that struck on Jan. 4.

That quake sparked a tsunami warning for hundreds of miles along the Alaska and Canadian coasts, but it was cancelled after a few hours when no damaging waves were generated.