PARKLAND, Florida－With tears, fears and defiance, students made an emotional return on Wednesday to their Florida high school where a former classmate went on a shooting rampage two weeks ago, killing 17 people.

Students at Marjory Stoneman Douglas High School in Parkland were greeted by heavy security and scores of well-wishers as they returned to classes.

In Washington, President Donald Trump surprised many by embracing a series of gun control measures that are tougher than usually supported by his party, and ordering lawmakers to work together on bipartisan legislation.

Dozens of police officers lined the sidewalks saying "Good morning" to each child and retired officers passed out flowers. Former students, neighbors and their children held banners reading "We Love You", "You've Got This" and "We Are With You".

"It's all a little overwhelming," said one 17-year-old student named William, who shared a classroom with two of the young victims, Nicholas Dworet and Meadow Pollack.

"It was just sad to go back there and not have my friends who were in the class with me anymore."

Likewise, for Kimberly Miller, the first day back meant confronting the absence of her geography teacher, 35-year-old Scott Beigel.

Beigel was one of three staff killed, along with 14 teenagers, when former student Nikolas Cruz entered the school on Valentine's Day and opened fire with a semiautomatic rifle.

"It's pretty upsetting," said the 14-year-old Miller. "But it was also refreshing to talk to everyone because people don't really understand how it feels, no matter how much they try to understand."

Since the shooting, Stoneman Douglas students have been lobbying politicians for stricter gun controls both in their home state of Florida and in Washington.

Republican lawmakers, with majorities in the US Congress and the Florida state legislature, have been cool on bringing in major reforms on the sales of firearms.

But Trump upped the pressure on lawmakers to get to work, hosting a bipartisan meeting at the White House where he raised eyebrows with his tough stance.

"We have to do something about it. We have to act," he said, voicing support for expanded background checks, more secure schools, curbs on the ability of the mentally ill to buy firearms and raising to 21 the age for buying certain guns.

"We can't wait and play games and nothing gets done."

At one point, he turned to a Republican senator and said: "You're afraid of the NRA," referring to the National Rifle Association, the premier US gun lobby.

Pressure is also growing on businesses. Walmart announced on Wednesday that it will no longer sell firearms and ammunition to people younger than 21 and would also remove items resembling assault-style rifles from its website.

The move comes after Dick's Sporting Goods announced earlier that it would restrict the sale of firearms to those under 21 years old.

"Our view was if the kids can be brave enough to organize like this, we can be brave enough to take them (the guns) out of here," said CEO Edward Stack.

AFP-AP