South Korea and the United States on Saturday started their search for any traces, including radionuclides or radioactive materials such as xenon, that could come from North Korea's latest nuclear test, military officials said.

North Korea conducted its fifth and largest-yet nuclear test in its northeastern region early Friday, sending ripples through the international community.

“The investigation team will engage in collecting and analyzing radionuclide exposure in the water and atmosphere,” a military official closely related to the matter said. 

The authorities expect that the collected samples will help in analyzing the composition of nuclear substances that was used in the North's nuclear test.

The South Korean Air Force launched light attack planes equipped with radionuclide detectors to gauge the level of atmospheric radionuclide exposure in its easternmost Gangwon Province.

In a similar move, the South Korean navy is set to dispatch a fleet with a radionuclide detector to the East Sea.

The retrieved radionuclide specimens will be sent to South Korean nuclear research institutions such as the Korea Institute of Nuclear Safety. The authorities will particularly look into whether North Korea used highly enriched uranium (HEU) for its nuclear detonation test.

The US military will also send a WC-135 radiation detection plane, which was on standby at a Japanese Air Force base in Okinawa, to the East Sea to collect radioactive samples from air blowing from the nuclear test site. (Yonhap)