NEW YORK (AFP) - A year after 20 schoolchildren were gunned down in Newtown, Connecticut, the small United States (US) town has asked to be left alone to mark the anniversary - and many media outlets are respecting their wishes.

On Dec 14, 2012, 20-year-old Adam Lanza went on a gruesome killing spree, using a military-style Bushmaster semi-automatic rifle to kill 20 children and six adults in about 10 minutes, after having already shot his mother to death at home.

The tragedy traumatised the US and continues to haunt the small east coast town.

Connecticut Governor Dannel Malloy asked for church bells to ring on Saturday at 9.30am (10.30pm, Singapore time), the moment Lanza opened fire a year ago. He also ordered flags to fly at half-mast all day.

Some Newtown families have planned to light candles on Friday night in memory of the victims, and a ceremony was held on Thursday in the National Cathedral in Washington.

President Barack Obama has also said he will hold a moment of silence at the White House on Saturday with his wife, Michelle.

But Newtown, a small city whose 28,000 residents are still deeply mourning, has purposely avoided planning any public ceremony for Saturday: no list of names will be read out - as is the case each year in New York for the victims of the September 11 attacks - and no speeches.

'NO MEDIA, POLICE, TAKE NOTICE'

Earlier this week, the city's top official, Ms Pat Llodra, asked the press to stay home, to allow families "the time to be alone and quiet, with time for personal and communal reflection". On Friday, the message to news outlets was clear, on signs visible across the city: "No media, police take notice", "No press" and "no parking."

Newtown has for a year been inundated by reporters. During the last three weeks, the media coverage has been particularly heavy.

The official report from the investigation into the shooting was published on Nov 25, sparking massive coverage but without answering just what motivated Lanza's horrific crime.

Soon after, authorities also released recordings of the 911 calls made from the school as the killing was underway.

"My plea is for the media to treat us kindly," Ms Llodra said before those tapes were released.

She asked reporters "to recognise that there is great personal pain in this event and little public good to be garnered through the general release", emphasising that her city was still living each day with the tragedy and needed time to move forward.

In an extremely rare move, most major US media organisations, including the main evening news broadcasts on ABC, NBC and CBS, did not play the recordings.

And though the broadcasters are covering the anniversary, they don't plan to go to Newtown.

"We will not be there on Saturday," a spokeswoman for CBS told the Agence France-Presse by telephone.

Likewise, NBC News is "respecting the town's wishes and our broadcasts have no plans to be in Newtown for the anniversary", a spokeswoman said over email.

Television channels CNN and ABC - as well as the Washington Post, the New York Times, and USA Today - have also said they won't send reporters to Newtown.

"We've reported a number of stories already - all in a low-key, respectful manner - and they'll run in conjunction with the anniversary. We do not plan to be in Newtown on the 14th," said New York Times communications director Eileen Murphy.

Previously, hordes of reporters have flocked to cover other first anniversaries of mass shootings, including the Aurora, Colorado movie theatre shooting, which left 12 dead on Jul 20, 2012, and the Virginia Tech shooting, which left 32 dead on Apr 16, 2007.

And as Newtown braced for the anniversary, news of another school shooting emerged: two students were injured at a high school in Colorado before the suspected gunman, also a student, apparently killed himself, local authorities said.