More than a decade after a mass shooting in a quiet Connecticut suburb, a group of survivors from Sandy Hook Elementary School are graduating from high school.

Twenty students and six staff members were killed in the shooting on 14 December 2012.

The youngest among them were six years old.

A private ceremony was held on Wednesday evening at Newtown High School, which around 60 survivors attended.

Graduating students spoke of complex emotions surrounding the milestone.

“The shooter actually came into my classroom. So I had to, like, watch all my friends and teachers get killed, and I had to run for my life at six years old,” Emma Ehrens told CBS News, the BBC’s US partner.

“Just growing up with having the fear, and the what-ifs of what could have happened if I stayed?” she said. “Because I was, like, I was going to be next.”

Another survivor, Lilly Wasilnak, said: “You wait for this day for your whole life, since you’re in kindergarten. You just can’t wait to graduate. And it felt so far away for such a long time… but I think we can’t forget about that there is a whole chunk of our class missing.”

A number of the survivors have volunteered for gun control groups and several met Vice-President Kamala Harris at the White House last week.

The mass shooting at Sandy Hook Elementary was carried out by a 20-year-old armed with two rifles and a handgun. He died from a self-inflicted gunshot as police arrived on the scene.

The US president at the time, Barack Obama, later called it “the single darkest day of my presidency”.

Following the murders, Mr Obama proposed a large raft of new laws designed to curb gun violence.

Although he implemented a series of reforms to the US background check system using executive orders, two major pieces of legislation failed to pass Congress.

The laws would have banned assault rifles and instituted background checks on most private gun sales. They had bipartisan support, but most Republican senators along with a number of Democrats voted against the measures.

The Sandy Hook shooting remains the deadliest ever at a US primary school.

Since the attack, there have been more than 4,200 mass shootings in the United States, including several dozen at schools, CBS reported.