Seoul, May 9 (IANS): North Korea launched two short-range ballistic missiles on Thursday, South Korea's military said, just five days after the communist nation launched a barrage of projectiles into the East Sea.

Pyongyang launched the projectiles at 4.29 p.m. and 4.49 p.m. (local time) towards the east, which had an estimated range of 420 km and 270 km respectively, before landing in the East Sea, also known as the Sea of Japan, South Korea's Joint Chiefs of Staff (JCS) said in a statement.

South Korea's presidential office expressed serious concern about the launches, saying they are "not helpful at all" to efforts to improve inter-Korean relations and ease military tensions on the peninsula, Yonhap news agency reported.

The South Korea's military statement added that it had detected that one of the projectiles was launched from Sino-ri and the other was launched from Kusong, in northwest North Korea.

Pyongyang's move adds yet another complication into its stalled negotiations with the US and peace talks with South Korea. The statement said the intelligence agencies of the US and South Korea were carrying out a detailed analysis of the launch.

Shortly after the first firing, Japan said no North Korean projectile had landed in its territorial waters.

Pyongyang latest weapons test shows the regime's harder stance after the deadlock in denuclearization dialogue following the failed February summit with the US in Hanoi.

Talks between North Korean leader Kim Jong-un and US Preside Donald Trump ended abruptly after Pyongyang proposed a gradual disarmament of the Korean peninsula with the progressive lifting of international sanctions.

The US, which is demanding a comprehensive and immediate disarmament, considered the proposition unacceptable. Since then, the regime has taken a harder stand towards the White House and Seoul.

The launch of such missiles violates the sanctions imposed by the UN, which ban North Korea from testing any kind of ballistic missiles or related technology.

North Korea had last week also launched several short-ranged missiles.

The new development coincided with the visit of US' Special Representative for North Korea Stephen Biegun to Seoul to discuss the situation on the Korean peninsula.

Experts said what Pyongyang launched on Thursday could have either been a Scud-type ballistic missile or a new type of ground-to-ground Iskander missile identical to that test-fired last week.