Recent satellite imagery shows little evidence that North Korea is preparing to conduct a nuclear test this week, but the communist nation could carry one out at any time with few indications, the website 38 North said Wednesday.

Concerns have grown in recent weeks that Pyongyang could undertake yet another provocation, such as a nuclear test and a long-range missile launch, to mark Friday's birthday of founding leader Kim Il-sung, grandfather of current leader Kim Jong-un.

"Recent commercial satellite imagery shows little evidence that Pyongyang is planning a nuclear test in the next few days.

Nevertheless, that possibility cannot be entirely ruled out since the North may be able to conduct a nuclear test on short notice with few indications that it intends to do so," 38 North said.

Imagery taken on April 9 of the North's Punggye-ri nuclear test site indicates the presence of a vehicle at the North Portal, where the North conducted its fourth nuclear test in January, as well as a few more vehicles at the main support area, 38 North said.

"The presence of the vehicle at the North Portal indicates continued activity in this area," it said.

In images from April 11, however, the vehicles were gone, it said, adding that its significance is unclear.

The images showed no apparent activity at either the South or West Portals, 38 North said. (Yonhap)