South Korea has deployed precision-guided land missiles capable of hitting North Korea's capital of Pyongyang, a military source said Friday.

The forward deployment of the surface-to-surface missiles, known as the Army Tactical Missile System (ATACMS), came as tensions rekindled after North Korea vowed a retaliation against the South's military over its use of head-shot photos of Pyongyang's top leaders as targets for shooting practice.

Several ATACMS missiles, which can be fired from multiple rocket launchers, have been positioned near the Demilitarized Zone dividing the two Koreas, the source said on the condition of anonymity.

With an effective shooting range of 165 kilometers, the missiles are able to pinpoint targets with a global positioning system and inertial guidance technology.

By 2004, the South Korean Army purchased some 220 ATACMS missiles from the United States.

North Korea has deployed hundreds of long-range artillery pieces along the border with South Korea, putting the South's capital of Seoul within striking distance.

The North's long-range guns and rockets are the biggest defense concern for South Korea as the capital and its neighboring areas, home to nearly half of the South's population of 50 million, lie about 50km from the heavily armed border.

Tensions on the Korean Peninsula spiked last year following the North's two deadly military attacks, which killed a total of 50 South Koreans. (Yonhap News)