South Korea said Friday that North Korea seems to have pushed ahead with its back-to-back launches of three mid-range ballistic missiles in a two-week period to build up the country's accomplishments ahead of the party congress next week.

Late Thursday, North Korea fired off two intermediate-range ballistic missiles (IRBM), but both attempts seem to have ended in failure, according to the South Korean military.

North Korea made its first botched move to launch the Musudan missile on April 15, the birthday of North Korean founding father Kim Il-sung.

South Korea's unification ministry said that the North's missile launches might be related to the need to show off the regimes accomplishments to its people.

"The North appears to have launched the missiles because North Korean leader Kim Jong-un might have ordered it ahead of the party event," Jeong Joon-hee, a ministry spokesman, told a regular press briefing.

He said that South Korea is keeping a close tab on the possibility of further provocations by the North.

Speculation is high that Pyongyang will conduct another nuclear test and launch more ballistic missiles in defiance of tougher U.N. sanctions.

Meanwhile, the ministry said that North Korea's Red Cross sent a notice on Thursday to its South Korean counterpart, which called for Seoul to repatriate 13 North Korean restaurant workers who defected to Seoul en masse early this month.

Ri Chung-bok, the chief of North Korea's Red Cross, has sent a message to his South Korean counterpart, Kim Sung-joo, calling for their prompt return.

The North has sent an email to the office of the International Committee of the Red Cross since the country cut off the main inter-Korean communication hotlines in February.

North Korea claims that South Korea kidnapped a group of workers of a North Korea-run restaurant in China. It notified the South last week that it will send their family members to Seoul for a face-to-face meeting.

The reclusive country, prone to saber-rattling, threatened to take strong action against South Korea if Seoul does not accept its demand for the families to meet and allow the workers to be repatriated.

"The North Korean restaurant workers defected to South Korea completely on their own free will," Jeong said. "The North should end its groundless claim and threats." (Yonhap)