A B-1B Lancer bomber deployed by the US military lands at Osan Air Base, south of Seoul, Sept 21, 2016. [Photo/IC]

SEOUL - The US military on Wednesday sent two strategic bombers to the Republic of Korea in a show of force against the Democratic People's Republic of Korea (DPRK) over its latest nuclear test.

Two B-1B Lancers flew low over the Osan Air Base in Pyeongtaek, some 70 km south of capital Seoul, at about 1:10 pm local time (0410 GMT), according to local media reports. The supersonic bombers had made a sortie from the US air base in Guam.

One of the two bombers returned to the Guam base after the fly-over, but the other unusually landed in the Osan base. How many days the US supersonic bomber will stay in the ROK is unknown.

On Sept 13, the US military dispatched two B-1B bombers to the ROK, but all of them returned back to the Guam base right after flying low over the Osan base for about 10 minutes.

The armed protests came after the DPRK said on Sept 9 that it successfully conducted an explosion test of nuclear warhead to fit on ballistic rockets. The fifth nuclear test was staged just eights month after the fourth in January.

The fifth test was seen as the most powerful nuclear detonation ever by the DPRK as it produced an explosive yield of 10 kilotons, stronger than 6 kilotons recorded in the previous test.

Pyongyang said Tuesday that it tested an engine jet on the ground of a carrier rocket for geo-stationary satellite, which Seoul military saw as a long-range missile.

The DPRK is expected here to launch a new long-range rocket at or around Oct 10 to mark the 71st anniversary of the founding of the ruling Workers' Party of Korea.