South Korea has recently detected a sharp increase in vehicle and human activities at North Korea's Punggye-ri nuclear test site and concluded the country is likely to carry out an additional nuclear test before early May, Yonhap quoted officials as saying on Sunday.

They said vehicles were seen moving in and out of the site's North Portal tunnel, and they may be carrying nuclear technicians.

One of the sources indicated that since the start of April, there has been a growing increase in the movements of cars and humans, adding that, "If they are signs of nuclear test preparations, it seems (the preparations) are in the final stages."

Concerns have been growing in recent weeks that Pyongyang could undertake additional military provocations like a nuclear detonation test as the country will hold its first congress of the ruling Workers' Party of Korea in more than 30 years in early May.

South Korea's officials are now closely monitoring the nuclear site to detect if North Korea is preparing to test a miniaturized nuclear warhead as the country has claimed. 

Source : MENA