An Amish community in Pennsylvania was in mourning on Tuesday after a truck driver described as "angry at life" gunned down 10 young girls at a rural schoolhouse, killing five.

Three girls died Monday at the school in Nickel Mines, about 100 kilometres west of Philadelphia, and two more died later in hospital. The gunman killed himself at the scene.

A state trooper looks inside the school where Charles Roberts shot several students and then killed himself in Nickel Mines, Pa.
(Mary Altaffer/Associated Press)

Five girls were in area hospitals with gunshot wounds to the head, legs and arms. Four were listed in critical condition early Tuesday, while one was in serious condition.

The victims ranged in age from six to 13 years. The dead have been identified as Naomi Rose Ebersole, 7, Anna Mae Stoltzfus, 12, Marian Fisher, 13, Mary Liz Miller, 8, and her sister, Lina Miller, 7. Two of the injured are aged eight, while the remaining three are aged six, 11 and 13.

Pennsylvania police said the girls were shot by Charles Roberts, a married father of three and milk truck driver who was apparently spurred on by a decades-old grudge.

The death toll increased at about 1 a.m. ET Tuesday when a girl died at Christiana Hospital in Delaware.

A fifth child died shortly after being taken off life support at Penn State Children's Hospital in Hershey. She died at about 4:30 a.m. ET.

"Her parents were with her," Amy Buehler Stranges, spokeswoman for the hospital, told the Associated Press.

Of the injured, a six-year-old remained in critical condition and a 13-year-old was in serious condition at Penn State Children's Hospital, spokeswoman Buehler Stranges said.

Three girls were flown to Children's Hospital of Philadelphia, where they were out of surgery but remained in critical condition, spokeswoman Peggy Flynn said.

Sean Young, a spokesperson for the Penn State Hershey Medical Center, which is associated with the Penn State Children's Hospital, said Tuesday that the girl in serious condition had made eye contact with her family.

"Generally speaking, any time you have a patient that goes from critical condition to serious condition, there is reason for optimism, but it's too early to say she is out of the woods at this point," Young said.

Amish not a target: police

Staff at the Penn State Children's Hospital stayed through the night after the shooting on Monday to provide medical care.

"This is a tragedy of a magnitude that our community is not used to seeing. There are a lot of moving parts. There are a lot of families involved," Young said.

"This is a terrible tragedy that affects all of us. It's very difficult."

State Police Commissioner Jeffrey B. Miller said Roberts was not targeting the Amish and the school was simply chosen because he wanted to kill young girls.

"This is a horrendous, horrific incident for the Amish community. They're solid citizens in the community. They're good people," he said.

"No one deserves this." 

Miller told NBC's Today that Roberts lost a daughter about nine years ago and that that may have been a factor in the shooting.

Miller said it was evident from the notes left behind and his telephone call that Roberts was "angry at life, he was angry at God," and co-workers had told police that he had undergone a personality change in recent days.

Wife recalls gunman as 'exceptional father'

In a statement released to the media, Marie Roberts, his wife, called her husband "loving, supportive and thoughtful."

"He was an exceptional father. He took the kids to soccer practice and games, played ball in the backyard and took our seven-year-old daughter shopping. He never said no when I asked him to change a diaper," she said.

"Our hearts are broken, our lives are shattered, and we grieve for the innocence and lives that were lost today. Above all, please pray for the families who lost children and please pray, too, for our family and children."

Nickel Mines is in the heart of what is known as Pennsylvania Dutch Country.

It is heavily populated by people observing the Amish faith, a type of conservative Christianity that emphasizes plain living and forbids acts of violence.

With files from the Associated Press