SEOUL - AN OFFICIAL of South Korea's spy agency says four North Koreans have defected to the South by boat and are being questioned.

The official of the National Intelligence Service said on Wednesday the defectors crossed the western sea border into South Korean waters on Tuesday.

He declined to give details and asked not to be named, citing the agency's policy.

Defections by boat are rare, with the vast majority who flee the hunger and harsh political oppression in North Korea travelling overland through China and South-east Asia to South Korea.

More than 14,400 North Koreans have arrived in the South since the Korean War ended with a 1953 cease-fire that has never been replaced with a peace treaty. -- AP