By Robert Weller
Associated Press Writer

Classes at Columbine High School were canceled today and Friday after a threat was made in an Internet chat room.

"One of our students received a warning-slash-threat through the Internet last night at their house," school district spokesman Rick Kaufman said. "In the interest of the safety and emotional well-being of our community, we canceled classes."

Kaufman would not comment on the nature of the warning, but he said it was directed at the whole school and not an individual student.

"It was about some kind of act that was to occur today at Columbine High School," Kaufman said.

The family of the student who receive the warning immediately contacted the sheriff's department and Columbine school security, he said.

Authorities "swept the building inside and out" but found nothing, said district spokeswoman Marilyn Saltzman.

It was the first time Columbine has been closed since classes began in August, four months after two seniors killed 12 students, a teacher and themselves in an assault on the suburban Denver school on April 20.

"Any threats, we take them very, very seriously now," Jefferson County sheriff's spokesman Steve Davis said. "We have to have almost zero tolerance."

Davis said the sheriff's department was investigating the threat. He also declined to give details.

Students had been scheduled to take final exams today in advance of the winter holiday break, and Friday was to have been a make-up day for those who missed exams earlier in the week.

Instead, students who drove up to the school in a stiff wind as dawn broke today were turned away. Others learned of the cancellation on television, the radio or from other students and parents.

"It's a really bad joke. Now we're going to have to study over the break," said Dan Goin, a senior who drove to school in a pickup truck. "But you never know, they may have saved all our lives today."

Kaufman said the finals will likely be rescheduled after classes resume on Jan. 5.

The threat came during an emotional week for Columbine community students, faculty and staff, Kaufman said.

He said the release to the media of videotapes made by Columbine gunmen Eric Harris and Dylan Klebold before their attack rekindled the pain, and the final exams and holiday season added to the emotion.

"It's not been a good week," he said.

Kaufman said there was extra security on school grounds Wednesday night in preparation for a concert that was scheduled to be held at Columbine tonight. He said no one had been allowed in and out of the building because of the concert equipment.

Officials had not determined whether they would cancel the concert.

While the closure was the first this semester, many students stayed away from school one day in October after a student allegedly threatened to "finish the job" Klebold and Harris started.

That student, whose name has not been released, pleaded guilty to misdemeanor charges and was ordered Monday to participate in a juvenile diversion program for one year. Prosecutors and the defense said he had seen a therapist who reported he was no threat to himself or others.