Lauren Abrams, 12, described what it was like when all Chester Academy High School and Middle School students were ordered to hold in place right as class was about to start.

Some students were arriving to school in buses and were told to hold in place.

Others who were already inside the school were informed the school would be on a lockout, keeping people from entering or exiting the building.

"So we stay on the bus for almost two hours," Lauren recounted. "Then a police officer said they're going to tell us to come off the bus and line up at the wall."

An official source told News 12 Thursday morning a parent called police, saying his child called him from a school bus to tell him another student might be bringing a gun to school.

Students and parents told News 12 explosive-detecting dogs sniffed all their bags, and then students were patted down.

Chester police said Thursday afternoon they and other agencies swept the entire school and found no weapons, which allowed classes to resume at about 10 AM.

Chester PD has not said whether any student was removed from the campus.

"It's unfortunate the kids who haven't done anything have to go through something like this," parent Michael Branbury said as he was exchanging texts with his son inside. "My son's scared to death. Apparently he's in a classroom with one teacher, because he went inside when they started making all the kids get back on the bus. He said he didn't feel safe."

Several parents said they were concerned about the searches of students and administrators' communication with families during the hold-in-place order, adding that they plan to share their concerns at next week's school board meeting.

The Chester Union Free School District said in a statement that, out of caution, some police stayed at the school well after the lockdown was lifted.

The district also reminded all students that "guidance or support services" are available to all students.

Chester Police did not return calls Thursday seeking comment beyond a statement the department sent out midday.

Several parents chose to sign their children out of school for the day, so many that there was a traffic jam of parents in cars as soon as the lockdown was lifted.