North Korea on Thursday launched two short-range missiles from its east coast, the South Korean defence ministry announced.
The North Korean People's Army fired two missiles into the East Sea, at 5.20 a.m. from the town of Wonson, in the southeast of the country, the South Korean Joint Chief of Staff said.
The missiles flew for around 500 km, EFE news reported.
"The military is keeping close tabs on the situation and is prepared to deal with any North Korean provocations," defence officials said.
The action comes after North Korea launched six short-range missiles which flew between 100 and 150 km into the East Sea on March 3.
On Monday, the US and South Korea began their annual joint exercises, the largest to date, which will last until late April involving about 315,000 troops from both the countries.
The Korean Peninsula is experiencing another period of high tension after Pyongyang conducted their fourth underground nuclear test on January 6 and launched a satellite aboard a rocket on February 7, after which the UN Security Council responded with tough new sanctions.