Washington/New York, Dec 15 (IANS): US President Barack Obama wiped tears from his face and spoke of his grief as the authorities raced to find answers to what led a heavily armed young man to storm a Connecticut elementary school and gun down 28 people, including 20 children.

Over 100 people have died in campus shootings across the US in the last two decades largely because of lax gun laws. The gun lobby is a powerful one in the US and no party is ready to take them on and repeal laws in which gun ownership is seen as a kind of fundamental right.

The children who were killed in Friday's mass shooting at Sandy Hook Elementary School in Newtown, over 100 km north of New York City, were said to be from 5 to 10 years old. Among the seven adults killed were Dawn Hochsprung, the school's principal, and school psychologist Mary Sherlach.

The shooter, identified by three law enforcement officials as 20-year-old Adam Lanza, also was killed, apparently by his own hand, CNN reported.

A 28th person was found dead in a house in the town and was also believed to have been shot by Lanza. That victim, according to a law enforcement official cited by the New York Times, was Lanza's mother, Nancy Lanza, a teacher at the school.

On Friday as a stunned America saw the unfolding tragedy in Connecticut, a student was arrested in the US state of Oklahoma for threatening to shoot inside a school.

Police arrested Sammy Chavez, 18, in west Bartlesville, Oklahoma, on an arrest warrant for threats to kill, reported Xinhua citing TV channel FOX23.

Police said officials from Bartlesville High School reported that a student talked about "planning a shooting at the school" Thursday morning.

According to court documents, the suspect tried to recruit other students to assist him in a plot to lure other students into the school auditorium, shut the doors and shoot them. Student witnesses also reported that the teenager claimed he would place bombs by the school doors.

With the toll at 28, the Newtown shooting is the second-deadliest school shooting in US history, behind only the 2007 shooting at Virginia Tech that left 32 people, including two Indians dead, and 17 others injured.

Authorities in Hoboken, New Jersey, questioned Ryan Lanza, the suspect's older brother, CNN said citing law enforcement sources. Lanza's father, who lives in Connecticut, was similarly questioned.

"I know there's not a parent in America who doesn't feel the same grief that I do," Obama, the father of two daughters aged 11 and 14, said as he stood at the podium in the White House press room, visibly struggling to keep his emotion in check.

"The overwhelming majority of those who died today were children, beautiful little children between five and 10 years old. They had their entire lives ahead of them. Birthdays. Graduations. Weddings. Kids of their own," he said.

Obama paused repeatedly as he spoke and the muscles near his right eye twitched as he worked to maintain his composure.

"Our hearts are broken today for the parents and grandparents, sisters and brothers, of these little children and for the families of the adults who were lost," Obama said.

The bodies of the young victims remained where they fell Friday night, as authorities worked to positively identify them.

"Evil visited this community today," Connecticut Governor Dan Malloy said of Friday's massacre.

Indian Americans too were shocked and heart broken over the massacre.

North American Punjabi Association (NAPA) said: "Our hearts go out to the victims and their families. Even the thought of such a catastrophic incident could not be conceived with the holiday season underway - a time to spread love and do charity. With the nation still overcoming the grief of the Wisconsin shootings, this incident has added to the pain."

Six Sikh worshippers were killed and three injured when a gunman opened fire at the Wisconsin gurdwara Aug 5. The gunman then shot himself in the head.

We are offering prayers for the victims of the shooting, said NAPA spokesperson Satnam Singh Chahal.

Chahal appealed to all Sikh gurdwaras to hold candle light vigils and to offer prayers for the families this weekend.

UN Secretary-General Ban Ki-moon too voiced his "deepest condolences" over the victims of the school shooting.

In a letter to Connecticut Governor Dan Malloy, Ban called the Sandy Hook Elementary School rampage "shocking murders", spokesman Martin Nesirky told reporters.