The terror of a school shooting hit this small rural town early today when a seventh-grader opened fire with a semiautomatic handgun at his middle school, wounding four students.

The victims are being treated at area hospitals, and none of the injuries are life-threatening, according to school and police authorities. A fifth student was treated for abrasions, but did not require hospitalization.

Law enforcement officials declined to identify the suspect, a student at Fort Gibson Middle School, because it was still unclear whether he would face charges as a juvenile or an adult. In the state of Oklahoma, that decision depends upon a determination of the boy's intent at the time of the shootings.

The Post's policy is not to identify juveniles charged with crimes unless they are charged as adults. Witnesses have described the alleged shooter as a popular honors student from a good family who recently celebrated his 13th birthday.

"This kid would have never entered my mind as someone who would do this," said Kim Davidson, whose daughter attends the high school in the same complex.

Keith Brickey, a student, told a local television station that it was a "shocker" when he heard the alleged shooter's name. "He's always been really nice to everyone . . . and really smart," Brickey said.

In Washington, President Clinton said federal investigators were on the scene. "Our prayers are with each of the children and their families," Clinton said.

Witnesses said the suspect arrived at the school before classes started and almost immediately began shooting a 9mm semiautomatic handgun. Police Chief Richard Slader said the department received the first emergency call at 7:47 a.m. CST.

"My son said he saw [the youth] drop his backpack, then he heard a pop and looked up and he was shooting," said Dawn Barnes, the mother of another seventh-grader. "Justin immediately laid down on the ground and shouted to his friends to get down. Of course, we had been through this after seeing the other school shootings on television. We told him he should lay low if someone starts shooting."

Richard Schindel, whose son was wounded, told the Associated Press that the suspect "did not say anything or make any accusations."

"All the kids started running. . . . It was only at that time my son realized he had been shot when one of his friends told him he had been shot. He looked down and saw the blood dripping from both his hands."

Within seconds, science teacher Ron Holuby confronted the suspect and told him to drop the gun, and he did so without incident, according to Slader. Holuby, also the school's safety officer, had the boy pinned to a wall when police arrived. The boy was immediately arrested and taken to jail. The police chief said the authorities were tracing the gun.

"He doesn't even know who it was he shot. This was not a hate thing. I asked him why. He said, 'I don't know,' " Muskogee County Sheriff's Deputy Terry Cragg told the Associated Press.

Slader said that the suspect showed no emotion on his way to the jail, and that he was not immediately questioned by police because of his age. Although the investigation is ongoing, Slader said, authorities believe the boy acted alone.

Both the middle school and high school were promptly shut down as frantic parents rushed to the schools to pick up their children. About 450 students attend the middle school in this town of approximately 4,000, 50 miles southeast of Tulsa.

The shooting was the latest in a string of unsettling attacks across the country by students on students. In the past few years, students have opened fire in schools in Conyers, Ga., Jonesboro, Ark., West Paducah, Ky., Pearl, Miss., and Littleton, Colo.

In the higher-profile cases, the shooters were found to have felt a sense of isolation from their classmates, such as the two teenage boys at Columbine High School in Littleton, Colo., who killed 13 people earlier this year before turning their guns on themselves.

But today, many students and parents insisted that there were no outward signs that the suspect was troubled. The youngest of three children, the boy was universally described as funny, good-natured and an athlete with no shortage of friends. Neighbors and friends also say he was an active member of his church, attending services with his family every Sunday. Several sources said he had a 13th birthday party at his house on Friday night. His father is a regional official of the Bureau of Indian Affairs.

He "was not a loner," said eighth-grader Rachel Lowry. "He was liked."

Two of the victims were taken to Tulsa hospitals for treatment, one a boy with gunshot wounds to both arms, and the other a girl with a gunshot wound to the cheek. Two other boys were being treated in nearby Muskogee, one for a wound to the leg and the other for a wound to the arm.

By early afternoon, the suspect was escorted through a crowd of reporters and onlookers to the local courthouse for a closed arraignment. Law enforcement officials declined to say what charges he faced.

Meanwhile, school superintendent Steve Wilmoth said that the schools will reopen tomorrow, and that the district has accepted the many offers from across the state and the country for counselors for the students.

"Like every other community, we felt it couldn't happen here," Wilmoth said. "We are all devastated."

Violence in School

Weapons and violent incidents are common on school grounds.

Schools reporting serious violent crime, 1996-97

City 17%

Urban fringe 11%

Town 5%

Rural 8%

Students expelled for firearms offenses, by school level, 1996-97

Total: 4,125

High school 56%

Junior high 34%

Elementary 10%

Students in grades 9-12 who reported carrying a weapon at least one day in past 30 days

1993 12%

1995 10%

1997 9%

SOURCES: Justice Department, Education Department

CAPTION: Officials investigate the crime scene outside Fort Gibson Middle School in Oklahoma, where a seventh-grader wounded four classmates with a 9mm handgun before a teacher stopped him.

CAPTION: Muskogee County Deputy Sheriff Philip Blair took a moment from the investigation to hug his daughter, Rachelle, a seventh-grader.