South Korean government sources tell Japanese NHK that satellite images and other data reveal increased activity “at a missile base in Musudanri, North Hamgyeong Province, in the northeastern part of North Korea.”
Check out the english language news segment. Kyodo apparently has a similar story.
Manichi cites Japanese Foreign Minister Taro Aso confirming the presence of a missile at the launch site, but not much else:
In fact, we understand that it has been brought to the site. But we are not sure about any subsequent moves. We are collecting information. The general information we have now is conflicting.
For more information, you might check out two posts that I wrote earlier, North Korean Ballistic Missiles and Can North Korea Mate a Simple Fission Weapon to the Taepo Dong 2.