Update 4.26pm Thousands of protesters have swarmed into the US capital and cities across the world to march for gun control and ignite political activism among the young.
Organisers of the March For Our Lives rally in Washington hoped their protest would match in numbers and spirit last year's Women's March, one of the largest Washington protests since the Vietnam era and one that far exceeded predictions of 300,000 demonstrators.
Bearing signs reading "We Are the Change", "No More Silence" and "Keep NRA Money Out of Politics", protesters lined Pennsylvania Avenue from the stage near the Capitol, stretching back towards the White House.
The route also takes in the Trump International Hotel.
President Donald Trump was in Florida for the weekend; a motorcade took him to his West Palm Beach golf club on Saturday morning.
After the February 14 mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida, students have tapped into a current of pro-gun control sentiment that has been building for years - yet still faces a powerful counterpoint from supporters of gun rights.
Organisers hope the passions of the crowds and the under-18 roster of speakers will translate into a tipping point starting in the midterm elections this year.
People also flocked to a March For Our Lives event near the Parkland school where the massacre happened. Police presence was heavy as organisers set up and demonstrators streamed in.
Eden Kinlock, 17, came from 20 miles away to pass out water, "a small thing but it helps in the bigger picture." Many Parkland students came to the Washington rally.
Hundreds of students & supporters are making their way down Columbus to Boston Common during Boston’s March For Our Lives this morning. Students are stopping along the way chanting “Enough is Enough!” & “Hey Hey NRA, how many kids have you killed today?” #MarchForOurLivesBoston pic.twitter.com/I6jaPPjdcb— Cristela Guerra (@CristelaGuerra) March 24, 2018
Washington is generally nonchalant about protests, but Saturday's gathering prompted more attention and speculation than usual. The protesters, many of them high school students, claim that the youth leadership of this initiative is what will set it apart from previous attempts to enact stronger gun-control legislation.
Polls indicate that public opinion nationwide may indeed be shifting on an issue that has simmered for generations, and through dozens of mass shootings.
A new poll conducted by The Associated Press-NORC Centre for Public Affairs Research found that 69% of Americans think gun laws in the United States should be tightened.
That was up from 61% who said the same in October of 2016 and 55% when the AP first asked the question in October of 2013. Overall, 90% of Democrats, 50% of Republicans and 54% of gun owners now favour stricter gun control laws.
“When a gun has more rights than you” ⚡️Today I stand in reverence of the students who’ve experienced such personal tragedy & used their voices to unite and action. Today we March For Our Lives. Today we reclaim our right to safety⚡️ Hope you can join/support #EnoughisEnough pic.twitter.com/MIgci6GIa1— Yara shahidi (@YaraShahidi) March 24, 2018
But even with claims of historic social momentum on the issue of gun control, the AP poll also found that nearly half of Americans do not expect elected officials to take action. Among the questions facing march organisers and participants will be how to translate this one-day event, regardless of turnout, into meaningful legislative change.
One way is by channelling the current energy into the midterm congressional elections this autumn.
Students in Florida have focused on youth voter registration and there will be a registration booth at the Saturday rally.
Earlier: Protests are taking place across the globe against school shootings and US gun control.
Rallies attended by children, students and families who have been affected by gun violence along with celebrities and members of the public are taking place as part of the March For Our Lives campaign.
Thousands of people are expected at a protest in Washington DC, including students from Marjory Stoneman Douglas High School where 17 people were killed in February.
America owes its gratitude to the students of Stoneman Douglas and their peers across the country who have joined their cause. We also owe them our support. Join #MarchForOurLives tomorrow to stop mass school shootings and give our kids their futures back. https://t.co/dqMASf6jgN— Bill Clinton (@BillClinton) March 23, 2018
Actresses Amy Schumer, Yara Shahidi, Connie Britton and Olivia Wilde are set to address crowds at the protest in Los Angeles.
A protest has been organised to happen outside the new US Embassy in London. The US flag flew at half mast at the previous embassy site after the Sandy Hook Elementary School shooting, in Connecticut, in 2012.
Amnesty International UK's director Kate Allen pointed to Britain's own experience of school killings with the Dunblane Primary School tragedy in 1996 in which 16 pupils and a teacher were murdered.
She said: "After our own school shooting at Dunblane, new gun ownership laws were introduced in Britain and that's exactly what's needed in the United States where gun deaths are a national tragedy.
"The White House must take responsibility for preventing future school shootings."
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"Having more random searches or more police isn’t real safety. As part of Students Deserve (@la_studentsdeserve), we are marching in solidarity with #MarchForOurLives to end all violence, including the school to prison pipeline and the over-policing in schools — especially the discrimination against black and brown students of color." -Sumaiya, high school junior, Zi, college freshman, and Jahlani, high school senior Share your story of why you are marching with the hashtag #IWillMarch
Campaigners are demanding that their lives and safety become a priority and are calling for an end to mass school shootings.
A statement on the campaign's website says: "Not one more. We cannot allow one more child to be shot at school. We cannot allow one more teacher to make a choice to jump in front of a firing assault rifle to save the lives of students.
It also adds: "School safety is not a political issue. There cannot be two sides to doing everything in our power to ensure the lives and futures of children who are at risk of dying when they should be learning, playing, and growing.
"The mission and focus of March For Our Lives is to demand that a comprehensive and effective bill be immediately brought before Congress to address these gun issues. No special interest group, no political agenda is more critical than timely passage of legislation to effectively address the gun violence issues that are rampant in our country.
"Every kid in this country now goes to school wondering if this day might be their last. We live in fear."