S. Korean business officials check on facilities in Kaesong complex KAESONG, North Korea, July 15 (UPI) -- Talks ended Monday without a deal on normalization of an inter-Korean industrial park in Kaesong, North Korea, an official in Seoul said. During the third round of discussions, South Korean negotiators reiterated their call on North Korea to guarantee the safety of South Korean businessmen who work at the park and to transform the complex into an international manufacturing zone, Yonhap News Agency reported. "The talks held in the North Korean border city of Kaesong did not lead to any understanding being reached," South Korea's Unification Ministry said. The two sides agreed to hold the next round of talks on Wednesday. Monday's unproductive talks came after last week's negotiations in which the two sides failed to agree on the resumption of activities of the park that that has been idle for more than three months. Earlier this month, the two countries agreed in principle to normalize operations at Kaesong. All operations at Kaesong ceased after Pyongyang withdrew all its 53,000 workers employed by the 123 South Korean plants in the industrial complex April 9. North Korean officials cited heightened tensions on the Korean Peninsula caused by the South as the reason for pulling the workers. Meanwhile, 159 South Korean businessmen, support personnel from utility companies and officials from the Kaesong Industrial District Management Committee returned to Seoul Monday after a check on their facilities, bringing with them finished goods and other production materials, Yonhap said. Under an agreement reached last week, North Korea said it would guarantee safe passage of South Korean businessmen into Kaesong. South Korean companies started bringing back products and some manufacturing equipment Friday.