South Korean companies operating in the Gaeseong Industrial Complex in North Korea are considering sending their South Korean employees back to the South.

A South Korean firm operating in Gaeseong said Monday that concerns have been rising over the safety of South Korean workers in the business park since Seoul announced last week that Pyongyang was behind the sinking of the “Cheonan” naval vessel.

The company said that it is considering allowing some of its South Korean workers to return to the South if they wish to do so.

However, no South Korean companies in Gaeseong have made an official announcement about whether their South Korean workers will be withdrawn from Gaeseong.

An official from another firm operating at Gaeseong said that some of the 700 to one-thousand South Korean workers who are in Gaeseong on a long-term basis could leave the North Korean city.

South Korean companies at Gaeseong have kept the number of personnel and vehicles commuting between the two Koreas at a minimum since last week.