Seoul, Feb 17 (IANS): At least four US F-22 stealth fighters flew over South Korea's airspace on Wednesday in an apparent show of force toward North Korea's recent nuclear test and rocket launch.

The nuclear-capable US fighter jets flew low over Osan Air Base near Seoul around noon, Xinhua reported.

The F-22 stealth fighters, which made a sortie from an airbase in Japan, were escorted by four South Korean F-15K fighters and four US F-16 fighters.

Two of them were set to return back to the airbase in Japan while the remaining were reportedly scheduled to stay at the Osan Air Base for the time being.

F-22 fighter, which has a stealth function of escaping radar detection, is capable of carrying nuclear missiles and bombs.

Its operational range reaches as far as 2,177 km. The F-22s deployed at a US airbase in Japan can fly to the Korean peninsula in about two hours.

The fly-over came in the wake of Pyongyang's launch on February 7 of a long-range rocket, which North Korea claimed was a peaceful space programme but Seoul and Washington denounced it as a prohibited test of ballistic missile technology followed by the fourth nuclear test on January 6.

Four days after North Korea's nuclear detonation last month, the US military sent a long-range B-52 bomber, capable of delivering nuclear bombs, over South Korea's airspace from the US air base in Guam.

The B-52 bomber can infiltrate at the highest altitude of 55,000 feet, or 16.8 km, carrying 35 conventional bombs and 12 cruise missiles.

It can deliver air-to-ground nuclear missiles with a range of 200 km and air-launched cruise missiles with a range of 2,500-3,000 km.

In addition, the US recently dispatched a nuclear-powered submarine to the Korean peninsula.

The USS John C. Stennis, a US nuclear-powered aircraft carrier, will reportedly be mobilised to South Korea during this year's joint annual war games between Seoul and Washington that will kick off on March 7 and run through April 30.