(Reuters) - An earthquake of magnitude 5.7 struck the southern area of Lake Tanganyika early on Friday, the U.S. Geological Survey said.

The epicenter of the quake, initially reported as a magnitude 6.1, was in a national park area in northern Zambia close to Lake Tanganyika.

The quake, which struck at 2:32 a.m. (0032 GMT), could be felt across the lake in Tanzania and to the north in the neighboring Democratic Republic of Congo, the USGS said.

It was very shallow, at a depth of only 6.2 miles (10 km), which would have magnified its effect, but a magnitude 5.7 quake is considered moderate.

(Reporting by Sandra Maler in Los Angeles; Editing by Leslie Adler)