Four North Korean asylum seekers have arrived in South Korea, some two weeks after they took refuge at a German government-run school in Beijing.

The North Koreans - one man and three women - landed at Incheon International Airport early Thursday morning aboard a Korean Air flight from Singapore.

German officials in Beijing had originally intended to hand over the defectors to Chinese police authorities, alleging that they had threatened diplomats' family members at the school with a knife. However, German officials said they later decided to send the group to South Korea on humanitarian grounds.

Almost 30 North Koreans have escaped to South Korea after seeking asylum at the German school in Beijing on three previous occasions since September, 2002.