A man with a pistol fatally shot three people on Friday, Dec 21 in rural western Pennsylvania, one of them in a church, before he was killed in a shootout with state troopers as he tried to flee in a pickup truck, authorities said.

Three state troopers also were injured in their confrontation with the gunman in Frankstown Township, about 100 miles east of Pittsburgh, shortly after 9 a.m. EST (1400 GMT), state police said.

The violence in Pennsylvania unfolded as bells tolled and many Americans were observing a moment of silence for the 20 children and six adults shot to death one week ago by a gunman at an elementary school in Newtown, Connecticut.

The Newtown shooter, 20-year-old Adam Lanza, also shot his mother to death at their home before going on his rampage, which ended with his suicide and has reignited a national debate over gun control.

The National Rifle Association pro-gun lobby marked the occasion on Friday with a statement urging that armed guards be placed at the nation's schools to improve security, Reuters reported.