Organizers are reporting as many as 800,000 people gathered in Washington, D.C., on Saturday afternoon for the anti-gun violence rally, NBC reported.
Rebecca Shabad, a congressional reporter for NBC News, tweeted that "March for Our Lives" officials told her the estimate around 3 p.m. Saturday.
D.C. metropolitan police have not yet released their approximate crowd size.
The current estimate of "March for Our Lives" attendees exceeds most estimates of President TrumpDonald TrumpUkraine's president compares UN to 'a retired superhero' Collins to endorse LePage in Maine governor comeback bid Heller won't say if Biden won election MORE's inauguration crowd size. The Washington Post estimated in 2017 that around 600,000 people attended Trump's inauguration.
Thousands of American students gathered all across the country, inspired by the student survivors of the Parkland, Fla., school shooting who organized the D.C. march.
Updated 3:46 p.m.