A 14-year-old shot himself in the face in a New Hampshire elementary school cafeteria filled with dozens of students eating lunch, officials said Friday.

The teen, who was not identified, was hospitalized after shooting himself around 11 a.m. at Walpole Elementary School in southwestern New Hampshire. Police locked down the school for several hours, but no one else was injured.

"Our hearts go out to the family of this young man and our thoughts go out to all of the students that were in the school at this time," Cheshire County Attorney Peter Heed said at a news conference. He did not say what kind of gun the student used or where he might have obtained it. He also did not offer any information on why the student shot himself.

As of Friday afternoon, the student was in serious condition in the intensive care unit.

Ethan Symonds, a seventh-grader who was sitting at a table near the boy in the cafeteria, said he heard something "a little bit louder than a chip bag popping." He said he did a double-take, saw blood, and ran.

Nick Phillips, an eighth-grader in the student's home room, said he had been passing notes during the week saying he was depressed, but it wasn't clear why.

Parents received automated calls about the lockdown at about 1 p.m. They were allowed to come to the school to pick up their children, some of whom were interviewed by police.

"The state of New Hampshire is offering whatever assistance it can to the community, along with all of our thoughts and prayers," Gov. John Lynch said in a statement.

Walpole is several miles from the Vermont state line and about 15 miles northwest of Keene.