The body of the gunman is carried from a schoolhouse in Nickel Mines, Pennsylvania October 2, 2006. A gunman killed three schoolgirls execution style and then shot himself dead on Monday after bursting into a one-room Amish schoolhouse in rural Pennsylvania, police said.  (Xinhua/Reuters Photo) Photo Gallery >>>

WASHINGTON, Oct. 2 (Xinhua) -- At least four people were killed in a shooting rampage at an Amish school Monday in Lancaster, Pennsylvania, CNN Television reported.

    The gunman, a 32-year-old milk truck driver named Charles Carl Roberts, had seized a dozen girls as hostage in the one-room school for about half an hour, before killing three of the hostages and himself as police tried to break into the house.

    Lancaster County Coroner's office initially said six people were killed, but Pennsylvania State Police Commissioner Jeffrey B.Miller later said the number should be four.

    At least seven people were taken to hospitals, including at least three girls in critical condition with gunshot wounds.

    Police said early in the morning, Roberts 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 a dozen girls inside.

    Roberts' wife said her husband assaulted the school in revenge for something that happened 20 years ago, but police said the gunman apparently focused on young female victims.

    The school, which has only 25 to 30 students in all, is surrounded by a white board fence and is about 88 kilometers west of Philadelphia.

    It is the third deadly school shooting incident in the United States since last week.

    On Friday, a school principal was gunned down in Cazenovia, Wisconsin, by a teenage student and on Tuesday an adult gunman held six girls hostage in a school at Bailey, Colorado, before killing a 16-year-old girl and then himself. Enditem