SEOUL (AFP) - It was a bad day at the office for one unfortunate employee of South Korea's weather service on Wednesday (May 18), after a mistakenly sent fax triggered an earthquake alert.

The message warning of a 6.5-magnitude quake was part of a five-day disaster response exercise and should never have been faxed.

International media, including China's official Xinhua news agency, ran the warning before the Korea Meteorological Administration (KMA) issued a red-faced apology.

"We apologise deeply for causing inconvenience," the KMA said in a statement quoted by South Korean news agency Yonhap, which also carried the initial alert.

"The message was made for an exercise purpose, and an employee mistakenly clicked the button to send the message."

The KMA released the message at 5.30pm local time, calling on residents in the affected area of Hoengseong in Gangwon province to evacuate.

Strong quakes are very rare on the Korean Peninsula.

Some seismological disturbances recorded in the South have been attributed to North Korean nuclear tests across the border.

South Korea also felt tremors when a strong earthquake struck Kumamoto in Japan earlier this year, prompting talk that the country might not be as safe from quakes are some may think.