An adult gunman took two female students hostage at Platte Canyon High School in the tiny Colorado mountain town of Bailey Wednesday, in a standoff that has lasted more than three hours.
"We have almost no information on this suspect," said Jacki Kelley, a spokeswoman for Jefferson County Sheriff's Office. "We don't know who is, we don't know what he wants."
The gunman initially took six hostages, but has released four since the situation began. Officials report two shots were fired, but no injuries.
"We are working on establishing more reliable communication with the suspect," she said.
Platte and the adjoining Fitzsimmons Middle School were being closed Wednesday after reports of shots fired. Schools in the surrounding areas were on lockdown. Around 4:30 p.m. ET, there were reports that a tank was brought in and aimed at the door of the school, as were the SWAT teams on scene.
The Jefferson County bomb squad and SWAT team responded to a reported emergency in Bailey, which is located about 50 miles southwest of Denver, according to local media reports. The two schools share a wall with each other.
There were reports that there was an "active gunman" in Platte. There are no reports of any injuries so far. Law enforcement officials are reportedly speaking with the shooter; it's not known whether those conversations are taking place in person or by phone.
Just before 2 p.m. ET, a man in his mid-30s entered the school, saying he had a bomb. One theory is that he may be a parent of a student.
The evacuation of the schools came after a loud noise, said Jan Howard, a secretary to the superintendent of schools.
"I don't know what the noise was," she said. She said students were taken to a safe location, but predicted parents would not be able to immediately reach them because the only highway in and out of town had been shut down.
Parents are being asked to pick up their children from nearby Deer Creek Elementary School.
"I'm just terrified. I'm terrified," said Sherry Husen, whose son plays on the high school football team and was told not to return to school from his part-time job. "I know so many kids in that school."
U.S Highway 285 was closed as crews respond to the scene, according to reporters on the scene.
According to the local Park County newspaper, The Flume, radio dispatch reports starting at about 11:45 a.m. indicated that an adult male had fired a shot in second-floor classroom after a teacher had refused to do what he asked.
The Flume reported that the dispatcher described a situation in which the male had a "black square-ish looking gun and fired one shot when the teacher refused to do what he asked." At 11:50 a.m., the dispatcher said the teacher had left the room five minutes before; students were in the room with the possible shooter.
Platte Canyon High School had 467 students enrolled during the 2005-2006 school year, according to its Web site. Fitzsimmons Middle School has about 350 students.
The schools are in a narrow, winding canyon carved by the South Platte River about 35 miles southwest of Denver.
Husen's family moved to Bailey from suburban Denver about 14 years ago.
"We moved up here for the mountain solitude, and I just never thought this would happen in this school, but it happens everywhere," she said.
Calls to Bailey police and the Park County sheriff were not immediately returned.
Bailey is located is in Park County, which is adjacent to Jefferson County. Jefferson County is where the Columbine High School shootings occurred on April 20, 1999. In those shootings, two students killed 13 people before taking their own lives. Jefferson County law enforcement has been called in to help Park County respond to the incident.
The Associated Press contributed to this report.