LOS ANGELES • Oprah Winfrey, George Clooney and Steven Spielberg are giving "ammunition" - in the form of US$500,000 (S$660,000) in donations - to the folks backing a campaign for gun control.

Gun ownership became a target again after the United States was rocked by last week's shooting at a Florida high school that left 17 dead.

Clooney and his wife, human rights lawyer Amal Clooney, were the first to make the financial pledge. They said they will also march alongside students at a rally in Washington, DC, on March 24.

Students from Marjory Stoneman Douglas High School in Florida, where a 19-year-old is accused of going on a rampage with a semiautomatic AR-15-style assault rifle on Feb 14, are assisting in planning the march.

The actor said in a statement: "Our family will be there on March 24 to stand side by side with this incredible generation of young people from all over the country, and in the name of our children Ella and Alexander, we're donating US$500,000 to help pay for this ground-breaking event.

"Our children's lives depend on it."

Later on Tuesday, Spielberg and his wife Kate Capshaw, as well as Winfrey, said that they would follow the Clooneys' move.

"George and Amal, I couldn't agree with you more. I am joining forces with you and will match your US$500,000 donation," Winfrey tweeted.

Spielberg and Capshaw said in a statement: "The young students in Florida and now across the country are already demonstrating their leadership with a confidence and maturity that belie their ages."

The March For Our Lives event on March 24 is one of several rallies being organised by students across the country in support of stronger gun laws, challenging politicians they said had failed to protect them.

REUTERS