The U.S. military on Wednesday sent two strategic bombers to South 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 p.m. local time (0410 GMT), according to local media reports. The supersonic bombers had made a sortie from the U.S. 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 U.S. supersonic bomber will stay in South Korea is unknown.

On Sept. 13, the U.S. military dispatched two B-1B bombers to South Korea, but all of them returned back to the Guam base right after flying low around the Osan base for about 10 minutes.

The move 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 eight months 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.

Several B-1B Lancers were reportedly dispatched to the Andersen base in Guam in early August from Ellsworth air base in South Dakota to replace B-52 strategic bombers.

The B-1B supersonic bomber, which went into operation in 1980s, is known to be capable of carrying as heavy as 61 tons of weapons, including joint direct attack munitions (JDAM), conventional bombs, air-to-surface missiles and cruise missiles.

The high-speed bomber can fly at a maximum speed of Mach 2, faster than B-2's Mach 0.9 and B-52's 957 kilometers per hour. It can travel as far as 12,000 km without refueling.

Three B-2 stealth bombers also arrived in Guam last month from Whiteman base in Missouri. The stealth bomber, which began to be deployed from 1990s in the field, can be armed with a maximum of 22-ton weapons, including 16 nuclear bombs and air-launched cruise missiles. It can travel as far as 12,230 km without refueling.

The B-52 bomber can travel as far as 16,000 km without refueling, carrying as heavy as 31 tons of weapons including nuclear bombs and "bunker buster" missiles that can destroy underground facilities.

Four days after Pyongyang's January test of what it claimed was its first hydrogen bomb, the U.S. military conducted an armed protest by flying a B-52 strategic bomber over the Osan air base.