Gun control marches are slated to be held Saturday in every U.S. state and on every continent except Antarctica.
While the main "March for Our Lives" rally is expected to draw more than 500,000 people to Washington, D.C., many more people are expected to join over 800 sibling marches worldwide, according to the group's website.
The march, organized by student survivors of the Parkland, Fla., high school shooting last month, is intended to demand lawmakers act on gun control and school safety.
Photos posted on social media Saturday morning from international marches showed young people in the United Kingdom, New Zealand, Japan, Sweden and other nations marching in solidarity with U.S. students.
Many celebrities, lawmakers and other prominent figures joined in the marches or donated to the movement in support of the students.