SEOUL, July 2 (Xinhua) -- The Democratic People's Republic of Korea (DPRK) fired four short-range missiles off its east coast on Thursday, South Korea's Yonhap News Agency reported.

DPRK fired the first missile at 05:20 p.m. (0820 GMT) and the other three at 06:00 p.m., 07:50 p.m. and 09:20 p.m. respectively from Sinsang-ni between the eastern coastal city of Hamhung and Wonsan, the report quoted a South Korean official as saying.

According to South Korean defense ministry spokesman Won Tae-jae, DPRK fired the short-range missiles off its east coast on Thursday, just hours after the DPRK ended its talks with South Korea without progress over their joint industrial park.

The missiles, which appeared to be surface-to-ship ones, "were fired into the East Sea (Sea of Japan)," Won Tae-jae said.

Other officials, who spoke on condition of anonymity, said the missiles landed about 100 kilometers off the coast, where the North had imposed a June 25-July 10 maritime ban for a military drill.

The firing is the first military action Pyongyang has taken since the UN Security Council passed a resolution bolstering sanctions on DPRK for its May 25 nuclear test.

Within several days of the nuclear explosion in May, Pyongyang fired a string of short-range missiles off its east coast. South Korea believed that Pyongyang is also preparing to test-launch an intercontinental ballistic missile.

Earlier Thursday, working-level talks between the North and South over their joint factory park in the North Korean border city of Kaesong ended without an agreement or a date for another round.

The park is the last surviving cross-border venture born out of the first summit between South Korea and DPRK's leaders in 2000, housing over 100 South Korean firms employing 40,000 workers from the DPRK.