Seoul – North Korea on Tuesday fired three ballistic missiles into its eastern sea in an apparent protest of South Korea's decision to allow the deployment of an advanced US missile defense system in the country, Seoul officials said.The missiles launched from a western North Korea town flew across the country before crashing into the waters off its east coast, Seoul's Joint Chiefs of Staff said in a statement.Two of them flew about 500km to 600km, displaying a sufficient range to reach entire South Korea, JCS spokesperson Jeon Ha Gyu said. He said South Korea's military was analysing how far the third missile flew. An earlier JCS statement said all three flew about 500km to 600km.A statement from the Pentagon said that US Strategic Command systems tracked "what we assess were three North Korean missile launches." It said two were presumed to be Scud tactical ballistic missiles, followed by the presumed launch of a Rodong intermediate range ballistic missile.It said the missile launches did not pose a threat to North America.North Korea routinely tests short-range missiles and artillery systems but the latest launches came days after the country warned of unspecified "physical counter-action" over the deployment of the Terminal High-Altitude Area Defense, or THAAD, system in the southern town of Seongju.Jeon said South Korea "strongly condemns" the launches that he described as an "armed protest" against the THAAD deployment.In Tokyo, Defense Minister Gen Nakatani said the launches were "an act of provocation that undermines regional and international security. ... We absolutely cannot accept it."StrikeNorth Korea has already deployed a variety of missiles that can reach most of South Korea and Japan, including American military bases in those countries. The country is also pushing to develop a long-range nuclear-tipped missile that can strike the mainland US, but South Korean defense officials believe the North does not possess such a weapon.Analyst Kim Dong-yub at Seoul's Institute for Far East Studies said the North appears to have demonstrated its ability to strike southern South Korean targets including an area where a THAAD battery is to be placed by the end of next year.A Rodong missile is known to have a maximum range of 1 300km. One of the missiles launched in March flew about 800km, according to Seoul's Defense Ministry.Seoul and Washington say they need the THAAD system to better deal with what they call increasing North Korean threats in the aftermath of its fourth nuclear test and long-range rocket launch earlier this year.The Korean Peninsula remains in a technical state of war because the 1950-53 Korean War ended with an armistice, not a peace treaty. About 28 500 US soldiers are stationed in South Korea to deter possible aggression from North Korea; tens of thousands more are stationed in Japan.