George Clooney has been visiting Southern Sudan amid war worries in the region.
His visit came three months before an independence vote that could see Africa's largest country break in two and spark a new, north-south war.
According to a blog post by Ann Curry, an NBC reporter who is accompanying the star, he said: "If you knew a tsunami, or Katrina or a Haiti earthquake was coming, what would you do to save people?"
The actor spent the past week travelling to remote, conflict-prone areas of Sudan's south with John Prendergast, the founder of the Enough Project, an anti-genocide advocacy group.
One photo showed the star pointing over a field that was the site of a mass grave from 2008.
He also visited the town of Malakal, where elements of Sudan's northern and southern armies have clashed twice since the end of the 21-year north-south civil war in 2005.