But Google and most Vietnamese websites remained accessible.

Telecom companies VDC, FPT, and Viettel said the quake had severed at least six international telecom cables beneath the sea south of Taiwan.

They were in touch with counterparts overseas to sort out the problem, but could not say when the situation would be resolved.

Asia-wide disruption

Disruption in service was reportedly Asia-wide, as other broadband service providers complained of similar problems.

Taiwan's largest telephone company, Chunghwa Telecom Co, said the damage had disrupted 98 percent of Taiwan's communications with Malaysia, Singapore, Thailand and Hong Kong.

Repairs to rectify the problem could take two to three weeks, said Vice-General Manager Lin Jen-hung.

Telecommunications companies in Hong Kong, Japan and China were also hit.

China's biggest telecoms provider, China Telecommunications Group, reported damage of communications cables to the US and Europe.

"Internet connections have been seriously affected and so have phone links and dedicated business lines," said a representative from the telecom group.

In South Korea, broadband provider KT Corp said six submarine cables had been disrupted, cutting services to a host of customers, including financial institutions.

Foreign exchange trading reportedly suffered as well.

Source: Thanh Nien, BBC – Compiled by An Dien