North Korea fired five short-range missiles into the East Sea on Sunday, South Korea's Joint Chiefs of Staff said, amid tensions ahead of next month's planned military drills between Seoul and Washington.

The projectiles were "presumed to be fired from its eastern border town of Wonsan in a northeastern direction for about 50 minutes from 4:20 p.m. in succession," JCS spokesman Jeon Ha-kyu said, adding that they flew some 200 kilometers before landing in the sea.

Sunday's firing is the North's second missile launch this year, after Friday's launch of anti-ship missiles under the guidance of its leader, Kim Jong-un, the JCS said.

"North Korea kicked off drills of the same kind two weeks earlier than last year," Jeon said. "(The South Korean military) will remain vigilant against additional launches while strengthening its joint surveillance posture with the United States."

While the military is analyzing details of the missiles and the intention of the launch, another military officer said that it is presumed to be "the North's new type of tactical missile that it test-fired last year."

The latest launch came ahead of the planned Seoul-Washington military drill scheduled in March, which Pyongyang claims is a "dress rehearsal for a northward invasion."

"It appears to be the North's saber-rattling, particularly after its relations with the U.S. have been deteriorating in recent months," the officer said.

The U.S. imposed fresh sanctions on North Korea over its alleged hacking attacks on Sony Pictures after it released "The Interview," a satire film which depicts a plot to assassinate the North Korean ruler. (Yonhap)