Future mass defection by North Koreans working abroad cannot be ruled out following the recent escape of 13 people, South Korea's unification ministry said Sunday.

Speaking to reporters, a ministry official explained that considerable pressure to send back hard currency to Pyongyang in the face of tough United Nations sanctions played a part in the restaurant workers' defection.

The government hinted earlier that the defectors were fearful that they would be punished if they were unable to send back money to North Korea. Many restaurants have been forced to close due to a drop in patrons, with estimates placing roughly half of them unable to send money back to the North.

He said the workers who had access to outside media, including TV shows, as well as Internet connection were aware of conditions in South Korea.

"Such information caused them to crave freedom and life in the South," the official, who spoke on condition of anonymity, said.

The insider then said that the one manager and 12 workers that arrived in Seoul on Thursday were all from upper middle class families, which in itself is meaningful.

"The move by such people holding status in the North is bound to have some impact on North Korea (as a whole)," he said.

On the current overall circumstances surrounding the Korean Peninsula, the ministry official said Pyongyang is continuing to show its defiance against the latest set of sanctions and could opt to lash out. This, he said, makes the present state very grave.

"Depending on how well Seoul handles the present situation, we can open a new chapter of change on the peninsula," he claimed.

The ministry said that with the U.N. sanctions taking bite, North Korea is finding it harder to carry out financial transactions, while many of its overseas operations have come under restrictions from foreign governments. It said even the shipment of money by couriers is becoming difficult with many foreign companies shying away from conducting transactions with North Korean counterparts for fear they too will be penalized.

North Korea is known to operate some 130 restaurants generating some US$10 million in cash inflow for the North Korean regime annually.

Related to the defection, Seoul's foreign ministry also clarified to the media the 13 North Koreans made their escape on their own.

The ministry sidestepped questions on whether it worked with foreign governments to expedite the defection, but emphasized it was the North Koreans who made the decision to flee.

There has been speculation that the North Koreans had passports with them so they were able to legally move across borders.

The ministry then said because there is a chance that other mass defections could take place, it is moving to work more closely with other governments to handle all eventualities. (Yonhap)