South Korea's military has lowered its surveillance alert level against possible aggression from the Democratic People's Republic of Korea (DPRK) by one notch from level two to level three, local media reported Friday, citing military sources.

The adjustment, made on Tuesday, came after Pyongyang reportedly lifted its order of special alertness for the Yellow Sea border areas recently, according to Seoul's state-run KBS broadcaster.

The DPRK ordered a special alert in November last year when South Korea was holding drills code-named "Hoguk Exercise".

The government and the military are studying whether Pyongyang' s move is related to its recent conciliatory gestures, Seoul's military sources were quoted as saying.

Meanwhile, the ROK-U.S. Combined Forces Command also lowered its WATCHCON surveillance alert from level two to level three as of Tuesday, according to the report.

South Korea raised its surveillance alert to its second-highest level, a state of emergency, after it exchanged artillery fire with the DPRK near Yeonpyeong Island on Nov. 23, which resulted in the death of four South Koreans.

Watchcon is a five-stage surveillance system in South Korea watching over the DPRK's military movements. The higher the level, the more spy satellites, reconnaissance planes and intelligence analysts are deployed on more frequent monitoring missions.

The DPRK recently offered a series of peace overtures, calling for unconditional dialogue with South Korea as soon as possible to "demolish misunderstanding and distrust as well as achieve peace and prosperity."