BAILEY, Colo. – A middle-aged gunman walked into the high school in this mountain town yesterday, fired at least two shots and took six people hostage before the situation ended with his death, authorities said. Hundreds of students were evacuated in a scene that recalled the horror at Columbine just a short drive away.

There were no immediate reports of injuries. Four hostages were released, but two girls remained inside the Platte Canyon High School more than three hours after the gunman arrived, said Jacki Kelley, spokeswoman for the Jefferson County sheriff.

The gunman was believed to be an adult between 30 and 50 years old. Kelley did not release his name or identify the hostages, but said the girls were believed to be unharmed.

“We have almost no information on this suspect. We don’t know who he is. We don’t know what he wants,” Kelley said, adding that officials had conducted sporadic negotiations with the gunman.

The high school and a nearby middle school were evacuated, and Jefferson County authorities sent a bomb squad and SWAT team to the high school. They are all too familiar with school attacks: The sheriff’s office handled the attack at Columbine.

Jan Howard, a secretary to the superintendent of schools, 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.

The sight of students fleeing the high school in long lines, and of frantic parents scrambling to find their children, evoked memories of the 1999 attack on Columbine High School, where two students killed 13 people before committing suicide.

“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.”

Parents pressed authorities for details but had little information on their children.

Bill Twyford said he received a text message from his 15-year-old son, Billy, a student at the high school, at about 11:30 a.m. It said: “Hey there, there’s a gun hijacking in school right now. I’m fine, bad situation though.”

Twyford said he had not heard from his son since then and was not sure if he was among the hostages.

Students from the two evacuated schools were taken to an elementary school for a head count. Ambulances were parked in the end zone of the school’s football field, and a tank-like SWAT team vehicle was parked nearby on a closed-down highway.

Michael Owens, who has one son at the middle school and another in the high school, said the anxiety was worse because of the memory of Columbine.

“It’s like an earthquake,” he said.

Tom Mauser, whose son Daniel was among the students slain at Columbine, said: “Any adult who holds kids hostage is reprehensible.”

The schools are in a narrow, winding canyon carved by the South Platte River about 35 miles southwest of Denver. They have an enrollment of about 770 students, with 460 in the high school.

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.

Other schools in the area were put in lockdown, meaning students would not be allowed to leave until administrators determined it was safe.

Lance Clem, spokesman for the state Department of Public Safety, said the gunman is dead, but had no details on his death or the condition of the two young girls.

Kelley declined to release details pending a formal news conference.