At least 27 people, including 18 children, were killed on Friday when at least one shooter opened fire at an elementary school in Newtown, Connecticut, CBS News reported, citing unnamed officials.
If confirmed, it would be one of the worst mass shootings in U.S. history. The holiday season tragedy follows a series of shooting rampages in the United States this year that have killed multiple victims, and it was certain to revive a debate about U.S. gun laws.
The principal and school psychologist were among the dead, CNN said. Witnesses reported hearing dozens of shots with some saying as many as 100 were fired.
The suspected shooter, 24, was armed with four weapons and wearing a bullet-proof vest, WABC reported.
There were unconfirmed reports of a second shooter.