Students rally at Marjory Stoneman Douglas High School after participating in a countywide school walkout in Parkland, Fla., on Feb. 21. (Rhona Wise/AFP/Getty Images)

Permit requests have been approved for an anti-gun-violence rally that could bring as many as 500,000 people to downtown Washington later this month.

The March For Our Lives rally, planned by survivors of last month’s school shooting in Parkland, Fla., will be held March 24 along Pennsylvania Avenue beginning at noon, although organizers expect participants will start to gather hours earlier. More than 700 “sibling marches” are also being planned around the world that day, according to the event’s website.

National Park Service spokesman Mike Litterst said an application was approved that includes usage of sidewalks along Pennsylvania Avenue NW between Third and 12th streets; sidewalks along Constitution Avenue NW between First and Ninth streets; green space between Constitution Avenue, Pennsylvania Avenue and Third Street NW; and John Marshall Park, the U.S. Navy Memorial and Freedom Plaza.

D.C. police said a separate permit filed with the city also was approved, although police didn’t make the permit available on Tuesday. Police said information about street closures would be released in the coming days.

The two permits were required because the sidewalks and parks along Pennsylvania Avenue are under federal jurisdiction, Litterst said. The rally is planned for Pennsylvania Avenue NW between Third and 12th streets, which is under the city’s jurisdiction.

Organizers initially had hoped to rally on the Mall, but a film crew was first to submit its application for that space. The Mall event was described in a heavily redacted Park Service permit application as a “talent show.”

Litterst said earlier this month that the permit was secured by a film crew “from a student group at a local educational institution,” but he wouldn’t identify the institution because “applications from educational institutions are withheld from release for privacy reasons.” The decision was criticized by civil liberties advocates.

“Those redactions seemed unreasonable and unjustified,” said Art Spitzer, legal director of the ACLU of the District of Columbia. “It may be sensible to protect the identity of juveniles — and the Freedom of Information Act allows for that kind of protection of personal privacy — but there’s no good reason to redact the name of the school . . . or the name of the adult sponsor.”

Litterst said the Park Service provided the film crew’s contact information to March For Our Lives organizers, as groups sometimes alter plans to accommodate larger events. The March For Our Lives permit application filed with the Park Service, for example, included 14 Jumbotrons, 2,000 chairs and 2,000 portable restrooms, while the film crew sought approval for equipment that included two tables, two bikes and jump ropes.

“I don’t know whether they ever reached out or not,” he said.

March For Our Lives organizers didn’t return requests for comment.