US: President Barack Obama embraced grief-stricken families of young children massacred in their school Sunday, at a moving vigil coinciding with rising demands for action on gun control.
Obama arrived in dark and chill Newtown, scene of Friday's carnage in which 20 children, aged six or seven and six adults died, and spent several hours privately consoling relatives of those murdered, and first responders.
Earlier, officials formally identified Adam Lanza, 20, as the shooter who ran amok in the picture postcard town and confirmed that he shot his mother several times in the head at the house they shared before going to his old school and embarking on a gruesome killing spree.
Queues stretched for at least 200 yards (meters) outside the auditorium at Newtown High School, where Obama was to attend a vigil later on Sunday evening and give an address.
Adults stood in groups, some crying and hugging, others joining younger children, many of elementary school age, in carrying teddies and cuddly toys as symbols of remembrance for young innocent lives ending in a hail of bullets.
Obama, representing a nation plunged into deep shock by the tragedy, was to speak at the end of the vigil, in a hauntingly familiar scene, consoling the bereaved from the fourth gun massacre of his presidency.
Lanza used his mother's Bushmaster .223 assault rifle to kill 26 people at the school, including 20 children aged either six or seven, before taking his own life with a handgun as police officers closed in and sirens wailed.
During his rampage, the shooter had four guns and multiple magazines, some holding up to 30 clips, but Connecticut State Police spokesman Lieutenant Paul Vance said it was unclear how many bullets were fired.
Connecticut's Chief Medical Examiner Wayne Carver has said that the bodies of the child victims were riddled with as many as 11 bullets.
Vance declined to hint at any possible motive they may have uncovered so far in their investigation, saying: "We don't have a specific reason we can stand here and say this occurred."
Grief mixed with new calls Sunday for action with the re-elected Obama under rising pressure to lead a charge to renew a ban on assault weapons and fast firing ammunition, and to take on the power of the US gun lobby.
A prominent Democratic lawmaker, Senator Dianne Feinstein of California, promised to introduce a bill to ban assault weapons on the very first day of the next Congress, January 3.
As he waited for the vigil to start in Newtown, Connecticut Senator Joe Lieberman called for a national commission on violence.
"These events are happening more frequently, and I worry that if we don't take a thoughtful look at them, we lose the hurt and the anger that we have now."
In ways big and small, tributes were paid -- from candles lit and teddy bears left at the elementary school crime scene, to gestures at the cavernous football stadiums that usually fixate Americans' attention on Sundays.
Before the day's games around the country, the National Football League had teams observe a minute's silence in memory of those killed.
Back in Newtown, nerves remained on edge. One Catholic church where people attended services -- Saint Rose of Lima -- was evacuated due to an undisclosed threat. Armed police searched a house next door.
Townsfolk poured into churches to pray and seek solace over the unimaginable -- a gunman pumping shot after shot into small children with a rifle of the kind used in wars.
The town Christmas tree became an impromptu place of remembrance, with people pausing every few minutes to pray and cross themselves under a light snowfall.
One middle-aged woman knelt down in front of the ranks of votive candles, teddy bears and handwritten notes, and bowed her head in tears.
"The community is gathering together and praying," Red Cross volunteer Rosty Slabicky told AFP.
"They are destroyed... Not just the families, but the first responders are dealing with the crisis on a very personal and emotional level."
The investigation entered a new stage with the autopsy of Lanza, seen as a withdrawn and awkward youngster who had shown no signs of violence, let alone any indications that he might perpetrate a massacre.
Lanza's main weapon was the Bushmaster, a civilian version of the US military's M4 -- legally registered to his mother. Police said he had three other weapons with him, two pistols and a shotgun found in a car.
Connecticut Governor Dannel Malloy revealed that Lanza blasted his way into the school, which had just installed a new security door where visitors could be viewed by video camera and buzzed in.
"He shot his way into the building. He penetrated the building by literally shooting an entrance into the building. That's what an assault weapon can do for you," Malloy said on CNN.
Many states, including Connecticut, already have strict laws on the purchase of firearms, but with no federal statutes, there is little to stop the traffic of guns from other states where fewer restrictions apply.
An assault weapon ban was passed in 1994 under president Bill Clinton but it expired in 2004 and was never resurrected. Obama supported restoring the law while running for president in 2008 but did not make it a priority during his first term.
"We have to come together and take meaningful action to prevent more tragedies like this," Obama said in his weekly radio address on Saturday. "Regardless of the politics."
However, with gun ownership protected by the constitution and firearms popular among a broad base of Americans, especially conservative Republicans, gun bans have long been seen as a vote-losing proposition.
Newtown was the second deadliest school shooting in US history after the Virginia Tech massacre in 2007 in which South Korean student Seung-Hui Cho shot and killed 32 people and wounded 17 others before taking his own life.
In the most notorious recent incident, a 24-year-old, James Holmes, allegedly killed 12 people and wounded 58 others when he opened fire at a midnight screening of the latest Batman movie in Aurora, Colorado, in July.