NEWTOWN, Conn. -

An official with knowledge of a shooting at a Connecticut elementary school says 27 people are dead, including 18 children.

A law enforcement official says the attacker in the Connecticut school shootings is a 20-year-old man with ties to the school.

The official spoke on condition of anonymity because the investigation is still under way.

The official said that a gun used in the attacks is a .223-caliber rifle. The official also said that New Jersey state police are searching a location in that state in connection with the shootings, said by an official in Connecticut to have left 27 dead, including 18 children.

The official in Washington spoke on the condition of anonymity because the source was not authorized to speak on the record about the developing criminal investigation.

Another official, speaking on condition of anonymity for the same reason, says the gunman is among the dead.

The killings happened at Sandy Hook Elementary School in Newtown, about 60 miles northeast of New York City.

State police say Newtown police called them around 9:40 a.m. A SWAT team was among the throngs of police to respond.

Photos from the scene showed young students -- some crying, others looking visibly frightened -- being escorted by adults through a parking lot in a line, hands on each other's shoulders.