North Korea's military appears to have lowered its alert level for the tense Yellow Sea border with South Korea, a government source here said Friday, after weeks of tension triggered by the North's bombardment of a southern island.

"The North Korean military recently lifted its order of special alertness for the Yellow Sea border areas it issued on Nov. 21 last year," the source said on condition of anonymity.

"Activities at the North's artillery units near the Yellow Sea border are believed to have been eased to the level seen before the order," the source said.

Accordingly, South Korea and the U.S. military stationed here also lowered their surveillance alert against North Korea to their third-highest level, Watchcon 3, as of Tuesday, the source said.    

South Korea and the U.S. had upgraded surveillance to Watchcon 2, a state of emergency at indications of a vital threat from North Korea, immediately after the North shelled Yeonpyeong Island, just south of the Yellow Sea border on Nov. 23, killing two marines and two civilians.

The South's military is analyzing whether the North's latest action is related to its conciliatory gestures in recent days.

In an annual New Year's message, North Korea called for talks with South Korea and a swift relaxation of tensions. On Wednesday, the North proposed holding "unconditional" talks with the South.

The gestures come as South Korea and its allies are exploring ways to revive six-party denuclearization talks that involve the two Koreas, the U.S., China, Japan and Russia. The talks have been stalled since the last session in December 2008.

South Korean officials have dismissed the North's offer of talks as an empty gesture, saying the North must apologize for its military provocations and show sincerity for denuclearization. (Yonhap News)