London Telegraph 
April 3, 2013
The abrupt set of exchanges came after Pyongyang shut down the last shared link with the South by refusing entry to almost 500 South Korean workers who work in a cross-border industrial park.
Zhang Yesui, the deputy foreign minister, outlined Beijing’s “serious concern about the present situation”, and added that it expects the escalation of tension to cease.
“All sides must remain calm and exercise restraint and not take actions which are mutually provocative and must certainly not take actions which will worsen the situation,” said the Foreign ministry.
The Kaesong complex lies six miles inside North Korea and houses 123 South Korean companies and their 53,000 North Korean workers.