South Korea's Joint Chiefs Of Staff (JCS) have reported that North Korea has launched three ballistic missiles off its eastern coast.
The JCS claimed the country had fired the missiles from an area near Hwangju region and they flew between 500km and 600km into the sea, media sources reported.
South Korea Prime Minister Hwang Kyo-ahn was quoted by BBC as saying: "The threat to our national security has grown very quickly in a short period of time.”
The move follows a recent decision made by the US and South Korea to deploy the Terminal High-Altitude Area Defense (THAAD) system to counter North Korean missile threats.
The THAAD will be able to shoot down short and medium-range ballistic missiles inside and outside the atmosphere.
The US military said that the latest launches involved two Scud missiles and one Rodong, Reuters reported.
Commenting on the launches, Middlebury Institute of International Studies senior research associate Melissa Hanham was quoted by Reuters as saying: "This smells political rather than technical to me.
"I think the number and distance of the missiles lets them remind the Republic of Korea (ROK) of what they are up against.”
The UN Security Council recently condemned the provocative actions by North Korea as the ballistic missile launches violate the resolution made by the 15-nation body.
The resolution prohibits North Korea's use of ballistic missile technology.