A leading Japanese daily says North Korea is likely to conduct another nuclear test around the end of July.

The Sankei Shimbun quoted a Japanese government official as saying Wednesday that the North has begun preparations to conduct its second nuclear test.

The paper added that after studying data regarding the North’s key Yongbyon nuclear reactor, Tokyo believes the North has resumed reprocessing spent nuclear fuel rods.

Pyongyang had been in the process of dismantling its nuclear facilities at Yongbyon until the U.N. Security Council officially denounced the North for a rocket launch on April fifth. In response, Pyongyang abandoned the six-way denuclearization talks and vowed to restart operations at the facility.

The North conducted its first nuclear test three months after test-firing its Daepodong missile in 2006 in the face of strong criticism from the international community on its rocket launch.