SEOUL, May 4 (Xinhua) -- South Korea's presidential Blue House expressed deep worry Saturday over the Democratic People's Republic of Korea (DPRK)'s launches of short-range projectiles, saying they escalated tensions on the Korean Peninsula.

Blue House spokesperson Ko Min-jung said in a statement that the South Korean government was deeply worried about the DPRK launches, which went against the purpose of the inter-Korean comprehensive military agreement.

The spokesperson urged Pyongyang to stop such launches that escalate military tensions on the peninsula.

The statement came after the DPRK fired unidentified short-range projectiles off its east coast Saturday morning.

Several projectiles were launched towards the northeast from the DPRK's east coast city of Wonsan for 21 minutes from about 9:06 a.m. local time (0006 GMT) Saturday, according to South Korea's Joint Chiefs of Staff (JCS).

The projectiles traveled some 70 km to 200 km into the eastern waters. Further details were being analyzed by the military authorities of South Korea and the United States.

Following the DPRK's projectile launches, the top national security advisor for South Korean President Moon Jae-in, the country's intelligence agency chief and the defense minister gathered at the national crisis management center to closely monitor situations and assess why the DPRK fired the projectiles.

The military authorities of South Korea and the United States currently shared detailed information on the launches, precisely analyzing what type of projectiles were fired, according to the Blue House.

The Blue House spokesperson said South Korea paid attention to the launches that came at a time when dialogue on the denuclearization of the Korean Peninsula came to a lull, calling for the DPRK to actively join efforts to rapidly resume the denuclearization negotiations.

She added that if necessary, South Korea will closely communicate with neighboring countries.

The projectile firings came as the second summit between top DPRK leader Kim Jong Un and U.S. President Donald Trump ended with no agreement in late February at the Vietnamese capital of Hanoi.

An unnamed South Korean military official was quoted by Yonhap news agency as saying the projectiles were not believed to have been ballistic missiles. The DPRK is banned from testing ballistic missiles under UN Security Council resolutions.

On April 17, the DPRK tested a new tactical guided weapon, which was not seen by South Korea as a ballistic missile.

It was originally alleged that the DPRK fired a short-range missile, but it was later revised into short-range projectiles. The last ballistic missile test by the DPRK occurred in November 2017 when the Hwasong-15 intercontinental ballistic missile (ICBM) was test-launched.

The JCS said the South Korean military intensified defense readiness and surveillance in preparation for the DPRK's possibly additional launches, adding that it maintained a full readiness in close cooperation with the United States.

Meanwhile, South Korean Foreign Minister Kang Kyung-wha exchanged opinions over phone with U.S. Secretary of State Mike Pompeo about the DPRK's projectile launches, according to Seoul's foreign ministry.

Kang and Pompeo agreed to conduct additional analyses on the launches and cautiously tackle it while continuing communications. Kang also held phone talks with her Japanese counterpart Taro Kono.

Lee Do-hoon, South Korea's special representative for Korean Peninsula peace and security affairs, talked over phone with Stephen Biegun, U.S. special representative for DPRK affairs, according to the Seoul ministry.

Lee and Biegun agreed to keep communicating with each other at every level about the issue. Lee also had telephone talks with his Japanese counterpart Kenji Kanasugi.