Factory zone block raises Korea tension

South Korean workers return home from the Kaesong joint industrial zone in the North.

They've been allowed to leave but Pyongyang on Wednesday suspended access to those trying to get to work.

Those arriving back on South Korean soil say some of their colleagues can't get transport home.

(SOUNDBITE) (Korean) A SOUTH KOREAN WORKER, WHO RETURNED FROM KAESONG INDUSTRIAL ZONE, SAYING:

"Other people couldn't return because they were supposed to leave by truck due to enter the North carrying supplies (THIS MAN SAYS) but they couldn't get in. I could leave, but not them."

More than 800 South Koreans stayed at the Kaesong complex overnight and most will do so again.

South Korea's unification ministry said the government was aware they could run short of food and other vital supplies in time.

(SOUNDBITE) (Korean) SOUTH KOREAN UNIFICATION MINISTRY'S SPOKESMAN KIM HYUNG-SUK SAYING:

"The government is well aware that such situation might arrive if thi