Another group of North Koreans who worked in a restaurant in China have defected and are waiting in a third country to come to South Korea, it emerged on Monday.

Their decision seems to have been triggered by the earlier defection of 12 waitresses and their manager from a North Korean restaurant in Ningbo.

"The North Korean restaurant workers arrived safely in a third country and should be able to arrive in Seoul this week," a source said.

A source in China said Chinese security forces are investigating the incident. There are conflicting reports on when and where the workers escaped, as well as their exact number.

Jang Jin-sung, a defector who edits the magazine New Focus International, said they were three women in their 20 who escaped from a restaurant in Shanghai.

But an intelligence source said that information "lacked credibility." Another source said they were two or three workers from a restaurant in Xian. The government merely said it is checking the information.