Taiwan ? Undersea fiber-optic cables were damaged by the powerful earthquake off the southern tip of Taiwan, causing the largest outage of telephone and Internet service in years and demonstrating the vulnerability of the global telecommunications network.

Two residents were killed and more than 40 injured in the magnitude-6.7 tremor that hit offshore, near the southern Taiwanese town of Hengchun on Tuesday.

Up to a dozen fiber-optic cables cross the ocean floor south of Taiwan, carrying traffic between China, Japan, Korea, Southeast Asia, the U.S. and the island itself. Chunghwa Telecom Co., Taiwan’s largest phone company, said the quake damaged several of them, and repairs could take two to three weeks.

Lin Jen-lung, vice-general manager of Chunghwa, said that four ships with crews to repair the two undersea data transmission cables ruptured in Taiwan’s powerful earthquake will arrive in the affected area on Jan. 2.

Taiwan lost almost all of its telephone capacity to Japan and mainland China. Service to the United States also was hard hit, with 60 percent of capacity lost.