North Korea fires five short-range projectiles into Sea of Japan

North Korea has fired five short-range projectiles into the Sea of Japan, South Korean officials said Monday.

The launches were first reported by the Yonhap News Agency. South Korea's Joint Chiefs of Staff reported that the projectiles were launched from the city of Hamhung, in northeastern North Korea, and traveled approximately 125 miles before landing in the water.

The South Korean military was attempting to determine whether the projectiles were missiles, artillery or rockets. Earlier Monday, Yonhap reported that the South Korean government had warned that North Korea was capable of conducting a fifth nuclear test at any time.

The latest launches appeared to be part of North Korea's response to ongoing South Korea-U.S. military drills it sees as a provocation and a rehearsal for an invasion. In the past two weeks North Korea has fired several short-range missiles and artillery shells into the sea and threatened pre-emptive nuclear strikes against Washington and Seoul.

This year's drills are the largest ever, and come after the North's nuclear test and long-range rocket launch earlier this year.