South Korea expressed doubts Friday about whether North Korea is sincere about holding inter-Korean dialogue, citing the North's firing of shells across the border.
  

North Korea called on South Korea Thursday to take "practical" measures to end its loudspeaker propaganda campaign against the North, threatening to take military action. At the same time, the North said that it has the intent to make efforts to open a channel for the improvement of inter-Korean ties.
  

The Ministry of Unification said North Korea's willingness for talks is questionable as the North sent strong warnings of military action against the South right after it delivered a message containing its intent for dialogue.
  

"We cannot help having doubts about North Korea's sincerity over holding dialogue with South Korea," Jeong Joon-hee, ministry spokesman, told a regular press briefing.
  

Jeong also blamed the North for denying its provocations, saying that the North's move is like "covering up the heavens with one's palm."
  

North Korea denied its firing of several rounds of artillery shells a day earlier across the heavily fortified inter-Korean border. The South fired back at the North, vowing to sternly deal with any further provocations from the North.
  

The North has so far slammed the South for spurning its offer for conditional talks while Seoul has called on Pyongyang to come to the talks without attaching any preconditions.
  

Amid growing tension on the Korean Peninsula, Seoul said ensuring the safety of South Koreans who are temporarily staying in the North has become top priority.
  

In a related move, the ministry has placed a partial ban on the entry of its nationals into a joint industrial park in North Korea.
  

The government said it has only permitted South Korean businessmen directly involved in the operations of factories at the Kaesong Industrial Park to enter the complex.
  

But other South Koreans, including those working as subcontractors, have not been allowed to move in and out of the complex in the North's border city of the same name, the ministry said.
  

"The government has allowed a minimum number of South Korean nationals to enter the industrial complex due to safety concerns," Jeong said.
  

A total of 124 South Korean small and medium-size enterprises operate factories at the industrial park, the last remaining symbol of inter-Korean reconciliation. About 54,000 North Koreans worker are currently employed there.
  

South Korean businessmen safely returned to the South from the complex on Thursday despite the North's provocations.
  

The ministry said that as of Thursday night, about 920 South Korean nationals are staying in the North, including historians involved in a joint six-month project to excavate an ancient palace and youth football players. (Yonhap)