SEOUL, May 4 (Xinhua) -- The Democratic People’s Republic of Korea (DPRK) fired unidentified short-range projectiles off its east coast Saturday morning, according to South Korea’s Joint Chiefs of Staff (JCS).

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), the JCS said in a statement.

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.

It was originally reported that the DPRK fired a short-range missile, but it was later revised into several short-range projectiles.

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.

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 ballistic missile.

It came after 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.

The last ballistic missile test was conducted by the DPRK in November 2017 when the Hwasong-15 intercontinental ballistic missile (ICBM) was test-launched.