WASHINGTON, Dec 14: As Americans experienced another school scare on the first anniversary of the Sandy Hook Elementary School mass shooting, President Barack Obama used the occasion to seek tighter gun control.

“We haven’t yet done enough to make our communities and our country safer,” he said in a recorded message. “We have to do more to keep dangerous people from getting their hands on a gun so easily. We have to do more to heal troubled minds.”

He added: “We have to do everything we can to protect our children from harm and make them feel loved, and valued, and cared for.”

On the eve of the first anniversary of the Sandy Hook shooting, a high school student in Colorado wounded at least two classmates before apparently taking his own life. He was armed with a shotgun.

Police said the gunman, Karl Halverson Pierson, 18, also brought two Molotov cocktails inside the Arapahoe High School and exploded one. The other was found and removed by the bomb squad. The shooting brought back the memories of the Sandy Hook tragedy and sent scores of terrified students and staffers scurrying.

On Dec 14, 2012, a mentally disturbed man killed 20 first graders and six staff members at Sandy Hook Elementary School in Newtown, Connecticut. Before driving to the school, Adam Lanza, 20, shot and killed his mother Nancy at their Newtown home. Then he committed suicide by shooting himself in the head.

“We lost 20 of our youngest students, and six dedicated school workers … to gun violence,” noted a White House press statement as President Obama once again appealed for tighter gun-control laws. He honoured those lost at Sandy Hook with a moment of silence at White House on Saturday while people across the country joined him.

The president also lit 26 votive candles in the Map Room — one candle for each of the children and staff members who were killed.

After the Sandy Hook incident, the Obama administration launched an aggressive effort to make stronger gun control legislation. But the effort failed when the US Senate rejected the proposed law earlier this year.