Students demanding tougher gun laws walked out of classes across the United States on Friday, the 19th anniversary of the shooting at Columbine High School which left 13 people dead.
As thousands of teenagers held rallies from coast to coast, a shooting at a high school in Ocala, Florida, left one student wounded.
The Ocala Star Banner newspaper said a 19-year-old former student at Forest High School fired a blast from a shotgun into a locked classroom door, wounding a 17-year-old student in the ankle.
The Marion County Sheriff's Office said the suspect, who was not identified, was quickly arrested.
Around the country, students marked the anniversary of the April 20, 1999 shooting at Columbine in Colorado, a massacre seen as the harbinger of an era of school violence.
"I feel like things have gotten worse these last few years," said Emma Corcoran, a 15-year-old from Bethesda-Chevy Chase High School in Maryland, at a rally in Washington. "Change needs to happen."
The protests have been galvanized by students at Marjory Stoneman Douglas High School in Parkland, Florida, where 14 teens and three adult staff members were shot dead on February 14 by a troubled former classmate armed with an AR-15-style automatic weapon.
The Parkland students have spearheaded a grassroots campaign for gun control which included another school walkout on March 14 and nationwide rallies by hundreds of thousands of Americans on March 24.
"So proud of the #NationalSchoolWalkout and all of the students around the country who are standing up for positive change and demanding what we deserve," tweeted Cameron Kasky, a Parkland student leader.
- 'Make our voices heard'
In Parkland, David Hogg, a Stoneman Douglas student, said he hopes the walkout inspires people to "get out and vote."
"That's what this country needs," Hogg said. "We just have to get out there and make our voices heard."
"I hope it inspires people to make a change," added Hogg's sister, Lauren. "I hope it shows people that although we're not old enough to vote yet, we're old enough to have a voice."
In Washington, several hundred students from area high schools rallied outside the White House and then marched on Congress to demand action on gun control.
Carrying signs reading "Enough Is Enough" and "Books Not Bullets," they chanted "We will vote" as they marched.
"A lot of people from my school came to show our support for increasing safety at schools and for better gun control legislation," said Matt Compton, a 15-year-old at Bethesda-Chevy Chase High School.
"I will vote for someone who I think will help solve this issue when I'm old enough," Compton said.
Former Arizona congresswoman Gabby Giffords, who was shot and seriously wounded by a gunman in 2011, sent a series of tweets supporting the students.
"After Columbine, America's politicians said, 'never again.' But after nearly two decades of inaction, it's clear they've failed in their basic duty to keep our kids safe," Giffords said.
"They are warning politicians to show the courage to address our gun violence or get voted out," she said.
Meanwhile, a group of Parkland students, activists and celebrities sent an open letter to the National Rifle Association pledging to take on the powerful gun lobby.
The "NoRA Initiative" said that it was aimed at "counteracting the influence of NRA money in the American political system."
Among those who signed the letter were the actors Alec Baldwin, Amy Schumer, Ashley Judd, Alyssa Milano and Julianne Moore and the activist Michael Moore.
An ABC News/Washington Post poll published Friday showed that support for a ban on assault weapons has risen sharply in the past few months.
Sixty-two percent of those polled said they support a nationwide ban on the sale of assault weapons, up from 50 percent in mid-February and 45 percent in late 2015.
Seventy-one percent of those surveyed said Congress is not doing enough to try to prevent gun violence and 59 percent said that President Donald Trump is not doing enough.