A milk truck driver took about 12 girls hostage in a tiny Amish school in the United States yesterday, killing at least three of them before turning the gun on himself.
It was America's third fatal school shooting in less than a week.
The 32-year-old gunman, Charles Carl Roberts IV, was in the building for more than half an hour and barred the doors, state police commissioner Jeffrey Miller said.
By the time officers had broken windows to get in, three girls and the gunman were dead. Seven others were taken to hospitals, three of whom were in a critical condition.
Mr Miller said: "It appears that when he began shooting these victims, the victims were shot execution-style in the head."
Roberts had walked into the one-room West Nickel Mines Amish School with a shotgun and handgun, then released about 15 boys, a pregnant woman and three other women with infants before barring the doors with the girls inside. The girls were lined up along a blackboard and had their feet tied with wire.
Roberts apparently called his wife from a mobile phone, saying he was "acting out in revenge for something that happened 20 years ago," Mr Miller said. "It seems as though he wanted to attack young, female victims."
Moments later, Roberts told police he would open fire on the children unless officers backed away from the building. Troopers heard gunfire seconds later.
The school has about 25 to 30 students, aged six to 13. At least seven people were taken to hospital, including three girls aged between six and 12 who were admitted to Lancaster General Hospital in a critical condition with gunshot wounds.
The small school, surrounded by a white board fence, is set in farmland just outside Nickel Mines, a tiny village about 55 miles west of Philadelphia.
The shootings were disturbingly similar to an attack last week at Platte Canyon High School in Bailey, Colorado, where a man took several girls hostage in a school classroom and then killed one of them and himself.
The 1999 Columbine High School massacre in Littleton, Colorado, remains the worst school shooting in America, claiming the lives of 15 people, including the two teenage gunmen. On Friday, a school principal was gunned down in Cazenovia, Wisconsin. A 15-year-old student, described as upset over a reprimand, was charged with murder.
Crime is rare among the Amish community, which was made famous after the Harrison Ford thriller Witness was set in a fictional Pennsylvania settlement. The Amish, who number about 180,000, have settlements in 25 American states and Ontario in Canada with 70% of the population in Ohio, Pennsylvania and Indiana. They practise a form of Christianity that emphasises piety, modesty and community derived from a literal reading of the Bible.
Because of their belief in separating their communities from the outside world, which they consider corrupting, they have strict regulations over customs. They tend to dress in simple, mostly dark, clothes, speak in a German dialect, and often shun technological innovation, including electricity, television, cars, telephones and tractors.