By Richard Valdmanis

BOSTON (Reuters) - Workers tearing down Sandy Hook Elementary School in Newtown, Connecticut, site of one of Americas worst school shootings, have been required by the town to sign confidentiality agreements barring them from discussing or photographing the site.

The move is aimed at protecting families of the victims from further airing of details of the incident in which a gunman entered the school last December and opened fire, killing 20 young children and six faculty and staff before turning his gun on himself, Selectman William Rodgers said.

"The town has already restricted access to the site among its own citizens, limiting access essentially just to families. Given that, a level of sensitivity is required among the workers too, and that is why we've done this," he said.

The town last month voted to accept a state grant of nearly $50 million to demolish the school and build a new one. Demolition, which will be conducted behind a screen perimeter to block onlookers, is meant to be completed before the December 14 anniversary of the shootings.

The mass killing prompted Connecticut, as well as neighboring New York and nearby New Jersey, to pass laws tightening their already restrictive rules on gun ownership. An attempt to pass stiffer federal laws died in Congress. Gun-rights advocates said tighter restrictions would harm law-abiding gun owners while doing little to deter crime.

Connecticut in September also released $5 million of an expected $15 million in state funding toward boosting security at school buildings, including installation of bulletproof glass, panic alarms, surveillance cameras and other technology.

That move came days after the United States experienced another mass shooting, when a gunman at the Washington, D.C., Navy Yard killed a dozen workers having breakfast before police shot him dead.

(Writing by Richard Valdmanis; editing by Andrew Hay)