Seoul, Apr 13 (IANS): New satellite photos have showed North Korea's nuclear base prepared and ready for a new test, something that would add to the rising tension in the peninsula, a monitoring group said on Thursday.

The photos of North Korea's Punggye-ri nuclear test site taken on Wednesday show continued activity around the North Portal (where earlier tests were conducted), new activity in the Main Administrative Area, and a few personnel around the site's Command Centre, US-based 38 North reported.

The analysis indicates that the volume of water that has been drained during the past weeks to keep the north gallery tunnel dry, has reduced in the last 10 days, Efe news reported.

No changes were observed in the spoil pile, so the excavation process might already be complete at the base located in Kilju county.

Experts have warned of continued activity in Punggye-ri for weeks and fear North Korea may soon carry out its sixth nuclear test, especially as important events are approaching with the country celebrating the fifth anniversary of leader Kim Jong-un's transition to power.

In addition, the country will commemorate the 105th anniversary of the birth of its founder, Kim Il-sung, on Saturday and the 85th anniversary of the founding of the Korean People's Army on April 25.

These celebrations coincide with increased tension in the peninsula after the US responded to the latest North Korean missile launch by sending a nuclear-powered aircraft carrier towards the peninsula.