SEOUL: North Korea moved long-range anti-aircraft missiles close to the border with South Korea as tensions rose over the sinking of one of Seoul`s warships, a newspaper reported Wednesday.

Chosun Ilbo quoted a military source as saying the North moved some SA-5 missiles from the southwestern province of Hwanghae to areas near the border, where they pose a potential threat to South Korean jets.

The missiles were repositioned around the time when the corvette sank in March, it said. A Joint Chiefs of Staff spokesman declined to comment on what he called military intelligence matters.

The aim seems to be to prevent South Korean planes from launching precision strikes on strategic targets in the North in any emergency, the source told the paper.

"When SA-5 tracer radar is activated, our fighters have to fly low to avoid detection. Their activities are consequently somewhat restricted," the source was quoted as saying.

With a range of 250 kilometres (150 miles), the missiles are a potential threat not only to South Korean aircraft operating near the border but those as far south as the central province of Chungcheong, the paper said.

The North reportedly purchased about 350 SA-5 missiles and 20 launch pads from the Soviet Union in the late 1980s.

Military tensions have risen since South Korea and the United States accused the North of torpedoing the warship, a charge it denies.

The South is Thursday starting a five-day anti-submarine drill in the Yellow Sea. The North has threatened "strong physical retaliation" for the exercise.

BDST: 10:10 HRS, August 04, 2010