Seoul: North Korea fired two short-range missiles into the sea Sunday, Seoul`s military said, in an apparent show of anger at an upcoming joint military drill between South Korea and the United States.
The North fired the two short-range ballistic missiles into the East Sea (Sea of Japan) at 1:20 and 1:30 am local time, the South`s defence ministry told AFP.
"Their range appear to be around 500 kilometres (310.7 miles)," he said, adding Seoul`s military had stepped up monitoring for additional launches.
The move -- the latest in a series of similar launches in recent weeks -- came a day after Pyongyang condemned an upcoming Seoul-Washington naval joint exercise.
The annual drill, to be held July 16 to 21, involves the US aircraft carrier George Washington, which arrived in the southern port of Busan on Friday.
The North bristled at the massive, nuclear-powered carrier visiting the port, calling it a "reckless" act of provocation on Saturday.
"The US should properly understand that the more persistently it resorts to reckless nuclear blackmail and threat, the further (the North) will bolster up its cutting edge nuclear force for self-defence," said the North`s top military body, the National Defence Commission.
The North has habitually slammed joint military exercises held south of the border and often responded with missile launches.
UN resolutions bar the North from conducting any ballistic missile tests. Sunday`s launch -- the fifth in just over two weeks -- took place in a sensitive area close to the heavily-fortified border with the South, the defence ministry official said without elaborating further.
Yonhap news agency said the missiles were launched only about 20 kilometres north of the demilitarised zone (DMZ) that has divided the peninsula since the 1950-53 Korean War ended in a fragile armistice.
The North appears to have moved them about 50 to 60 kilometres away from a military base by using mobile launchers, Yonhap said, citing an unnamed Seoul army official. The location may fall within the range of South Korean artillery guns, said Kim Jung-Bong, a political science professor at Hanzhong University, adding the move was aimed at portraying the North`s leader Kim Jong-Un as a "bold leader with guts".
"The North appears to be stepping up its threats by showing that it can fire missiles at any time and any place it wants," said Kim.
The North has often fired short-range missiles or rockets into the sea to express anger at perceived provocations.
Previous tests had preceded Chinese President Xi Jinping`s state visit to Seoul, and were seen by some analysts as a show of pique at his decision to visit Seoul before Pyongyang.
China is the isolated North`s sole major ally, but while Xi has met four times with South Korean President Park Geun-Hye, he has yet to sit down with Kim Jong-Un.
Japan lodged a protest to Sunday`s launch with the North via the Japanese Embassy in Beijing, South Korea`s Kyodo News and Japan`s Jiji Press said.
But Prime Minister Shinzo Abe told reporters that the missile launch would "not affect" Tokyo`s ongoing talks to solve the issue of Japanese abductees in the North, according to Jiji.
Dozens -- or even hundreds -- of Japanese citizens are known to have been snatched by North Korean spies to train their agents in language and customs during the 1970s and 1980s.
Tokyo earlier this month vowed to lift some of its sanctions on the North as Pyongyang promised to re-investigate the disappearances of Japanese citizens.
In between the recent launches, Pyongyang has also made several peace overtures to Seoul, including a proposal for both sides to halt all provocative military activity.
The South dismissed the offer as "nonsensical" in the light of Pyongyang`s nuclear programme and reiterated that the annual joint drills are non-negotiable.
But it accepted another offer by Pyongyang to send a delegation of cheerleaders to support North Korean athletes during the September 19-October 4 Asian Games in the South.
Seoul last week proposed to hold talks to coordinate the trip at a border truce village of Panmunjom on Thursday.