PASADENA, Calif. (AP) — A high school student was in custody Saturday after a daylong school lockdown caused by witness accounts of a gun in his hand, authorities said.

Police arrested the male student, whose name was not released, on suspicion of carrying a weapon Friday. He was taken into custody for investigation of being a minor possessing a firearm, police said in a statement.

No weapon has been found, but there was probable cause to arrest the student, including witness accounts that the youth was carrying one, Lt. Jari Faukner said.

Police said the investigation was ongoing and another search could be conducted later.

SWAT teams were sent to Blair International Baccalaureate School shortly before 9:30 a.m. Friday after a student reported seeing someone walking on campus with a gun in his waistband.

As a precaution, all 1,200 students were confined to classrooms for hours as police searched the campus, formerly called Blair High School, "looking room by room, hallway by hallway, bush by bush," police Lt. Tom Pederson said.

Anxious parents waited outside for hours until their children began being released after 5 p.m.