Sept. 7 (Bloomberg) -- A magnitude 6.5 earthquake struck off the coast of Taiwan about 115 kilometers (70 miles) southeast of Taipei at 1:51 a.m. local time, the U.S. Geological Survey said on its Web site.

The earthquake was 63 kilometers deep, the agency said. Taiwan's Central Weather Bureau said a second quake followed four minutes later with a magnitude of 5.7. No tsunami alert was issued and there were no reports of injuries.

``It was a fairly shallow quake,'' Don Blakeman, a seismologist at the USGS in Colorado, said in a telephone interview. ``It could shatter the glass of some windows and the people there definitely felt it.''

Chunghwa Telecom Co., Taiwan's biggest phone company, said an undersea fiber-optic line located 100 kilometers off Hualian, Taiwan, was damaged. The cable handles calls to Hong Kong, South Korea and Japan, Lo Kuang-chuan, the director of the phone company's international fiber optic business, said in a telephone interview today.

Chunghwa Telecom restored all overseas calls by rerouting at 2 p.m. and expects to repair the damaged cable within three weeks, it said in an e-mailed statement.

Taiwan Semiconductor Manufacturing Co., the world's largest maker of custom chips, reported no immediate damage from the quake, according to spokesman Tzeng Jinn-haw.

Taiwan, which lies in a zone where the Philippine and Eurasian tectonic plates meet, gets shaken by an average of 200 earthquakes a year, according to the local bureau. Quakes occur as tectonic plates push together. Magnitude 6 quakes can cause severe damage, depending on their depth.

A magnitude 7.1 quake struck Taiwan on Dec. 26, killing two people, cutting power and disrupting phone and Internet services throughout Asia.

To contact the reporters on this story: Kelly Riddell in Washington at Kriddell1@bloomberg.net; James Peng in Taipei at jpeng7@bloomberg.net

Last Updated: September 7, 2007 04:51 EDT