School students across the United States walked out of their classrooms on Thursday morning (AEDT) in support of a protest by Florida shooting survivors against their country’s gun laws.

Shooting survivors joined hundreds of protesters chanting “vote them out” at a #NeverAgain rally outside the Florida capitol building in Tallahassee to support a bill to ban the sale of assault rifles.

Police say a 19-year-old-man used a semi-automatic AR-15 assault rifle to kill 17 students and teachers at Marjory Stoneman Douglas High School last week.

Massacre survivor Delaney Tarr spoke at the Florida rally saying she wanted action, not just words.

“We’ve had enough thoughts and prayers,” she said.

“If you supported us, you would have made a change long ago. So this is to every lawmaker out there: No longer can you take money from the NRA. We are coming after you. We are coming after every single one of you, demanding that you take action.”

Fellow Stoneman Douglas student Florence Yared said she wasn’t trying to “take away your right” to bear arms. “But we cannot protect our guns before we protect our children”.

“The only purpose of an assault weapon like this is to kill, and to kill as many people as possible,” the 17-year-old said.

“The AR-15 is not a self-defence weapon. It is called an assault weapon. Assault. Think about this word.”

Hundreds of students across Tallahassee rally in the wake of the deadly shooting at Marjory Stoneman Douglas High School last week, asking for gun control legislation. https://t.co/gm2Hc3hyrZ pic.twitter.com/MxQRie8fzH

— ABC News (@ABC) February 21, 2018

Thousands of students across Florida walked out of their classrooms in solidarity with the shooting survivors’ protest.

Their gesture was followed by similar reported walkouts in Washington DC, Maryland and California, where classrooms emptied in support of the Florida students.

Schools in the Texas district of Needville told students they would be suspended for three days if they walked out of class amid reports of other schools across the country making similar threats.

“We want to see some common sense gun laws so this will never happen again,”  Rachel Padnis, a 16-year-old student said.

The state Senate on Wednesday postponed discussion on a proposed gun control bill, with Senate president Joe Negron, a Republican, saying the chamber will take up other measures. The legislative session wraps up on March 9, leaving lawmakers little time to act.

Before that move, dozens of students packed into a meeting room and peppered Mr Negron with questions about why civilians should have continued access to assault rifles.

Mr Negron declined to say whether he would support any specific gun control measures, saying: “That’s an issue we’re going to look at as we work to develop legislation.”

Under pressure after the Florida shooting, Mr Trump on Tuesday directed the Justice Department to quickly complete a proposed rule that would treat “bump stocks” as machine guns, which could effectively outlaw them in the US.

Calls for national student walkouts and marches in the coming months have gained momentum on social media, including the proposed “March for Our Lives” on March 24 in Washington, spearheaded by Marjory Stoneman Douglas students.

– With AAP