South Korea's military said Monday that it has detected signs indicating that North Korea carried out a military parade in time for a ruling party congress in Pyongyang late Sunday.

The North has been holding the eighth congress of the Workers' Party in Pyongyang since Tuesday, and the possibility has been raised that it could stage a military parade on the occasion.

"Our military detected signs that North Korea held a military parade related to the party congress at Kim Il-sung Square in Pyongyang late at night yesterday," the Joint Chiefs of Staff (JCS) said in a release.

"South Korea and US military authorities are closely following them, including possibilities that the activity could be a rehearsal," it added.

The types of weapons involved were not immediately known.

The communist country last held such a parade on Oct. 10 last year to mark the 75th founding anniversary of the ruling Workers' Party and unveiled a new intercontinental ballistic missile (ICBM) and a submarine-launched ballistic missile (SLBM), along with diverse military assets.

The October event took place in the wee hours, and Pyongyang broadcast the recorded footage the following day.

A source in Seoul said the latest one appears to have been held in a scaled-back manner due to various circumstances, such as the COVID-19 situation, a cold wave, and its military's ongoing regular wintertime drills.

During the congress, leader Kim Jong-un said that his country is developing new weapons systems such as a nuclear-powered submarine, advanced warhead and hypersonic weapons, according to the Korean Central News Agency (KCNA).

Calling the United States "the foremost principal enemy," the North made it clear that it will continue to beef up its nuclear arsenal without interruption. Pyongyang also revised ruling party rules to stress the importance of powerful defense capabilities.

Asked about assessments about those armament claims, South Korea's defense ministry said Monday that analysis is under way about the North's reports without providing further details. (Yonhap)