A Japanese daily says an increase in activity has been detected around the North Korean town of Punggyeri in Gilju County, North Hamgyeong Province, where Pyongyang conducted its second nuclear test in May of last year.

The Sankei Shimbun on Wednesday quoted British military intelligence firm “Jane’s Information Group” as saying that satellite images taken by Digital Globe of the U.S. on October 16th showed vehicle activity and changes in facilities near the underground nuclear test site in Gilju last month.

The report added that images taken on October 27th showed freshly dug gravel and soil covering areas of some three-thousand square meters at a spot some 150 meters south from the nuclear test site. The paper said signs of earth being dug up were also detected at a spot some 180 meters north of the nuclear test site.

The paper quoted Jane’s as saying that the North seems to be preparing for another nuclear test and that given the conditions detected so far, something is expected to happen in the North within half a year.