North Korea has fired a short-range missile into the Sea of Japan, a Seoul military official said, one day after firing three short-range guided missiles. Meanwhile, South Korea has deployed precision-guided missiles on its border islands.

Seoul has placed Israeli precision-guided missiles capable of hitting North Korean targets on its Yellow Sea border islands, Yonhap news agency reported Sunday.

"Dozens of Spike missiles and their launchers have recently been deployed on Baengnyeong and Yeonpyeong islands," an official for the Joint Chiefs of Staff (JCS) said. "They can destroy [North Korea's] underground facilities and can pursue and strike moving targets."

The satellite-guided Spike missile has a range of about 20km (12.4 miles) and weighs 70kg (154lbs), according to military officials.

Yeonpyeong is situated just 11km (6.8 miles) from North Korean shores.

North Korea's artillery sub-units (Reuters / KCNA)

South Korea moved to place the Israeli missiles after Seoul confirmed that North Korea on Saturday had launched three short-range guided missiles off its east coast into the Sea of Japan. 

Japan confirmed the report of the launches, saying its military had detected them as well.

Two launches were fired on Saturday morning and another one in the afternoon, the Yonhap news agency reported.

Media reports speculated that the projectiles were likely shore-based anti-ship KN-2 Toksa missiles, North Korea’s version of the Soviet-made OTR-21 Tochka tactical ballistic missile, which Pyongyang is believed to have reverse-engineered.

"The missiles traveled about 120 km and in the North Korean arsenal, only the modified KN-02 or multiple rocket launchers of 300 mm or larger in caliber can go that far," a source in the South Korean government said.

Seoul condemned North Korea's latest short-range missile launches as "provocative."

North Korea has not commented on the launches.

While the latest test launch only involves short-range missiles, it poses security threats to the region and should be "stopped immediately,” said the Seoul ministry that is charged with cross-border affairs.

"We find it deplorable that the North does not stop provocative actions such as the launch of guided missiles yesterday," said Unification Ministry spokesman Kim Hyung-Seok.

"We call on the North to take responsible actions for our sake and for the sake of the international community."

UN Secretary-General Ban Ki-moon expressed concern over the missile launches and urged Pyongyang to return to talks on the nuclear issue in the six-party format.

"We are very concerned about North Korea's provocative actions," Ban told reporters in Moscow on the weekend. "I hope that North Korea will refrain from any further such actions.”

The UN Secretary General said hopes that Russia "will continue to use their contacts to reduce tensions and intensify the dialogue with North Korea."

He said that he had discussed this subject matter in a meeting on Friday in Sochi with Russian President Vladimir Putin.

A South Korean navy destroyer (Reuters / South Korean Navy)

Meanwhile, the US State Department Saturday called on the North to exercise restraint, without specifically mentioning the launches.

The US stations around 28,500 troops in South Korea, a carry-over from the 1950-53 Korean War, which ended with an armistice, not a peace treaty, between the warring sides.

The Korean Peninsula is emerging from the latest episode of tensions, which began February 12, 2013, when Pyongyang announced it had conducted an underground nuclear test, its third in seven years.

The test was met with harsh international condemnation and a new round of sanctions by the UN Security Council.

South Korea and the US responded with large scale naval maneuvers, which Pyongyang called a provocation and threatened to use its nuclear arsenal if attacked.

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