A North Korea-focused news site reported Tuesday on the "unusual" activity throughout April of leisure boats often used by leader Kim Jong Un in the coastal resort of Wonsan, suggesting his presence there amid ongoing speculation about his health.

NK News said satellite imagery showed this week that the boats "have been active throughout this month and made unusual moves" around the time of April 14, when Pyongyang is believed to have carried out a missile test.

When the boats relocate from central Wonsan to where his villa is situated, "there has been a high correlation with Kim's public appearances in the area," the news site said.