Students at Philadelphia's community college sheltered in place Tuesday morning after police said a man threatened a student with a gun and then ran into a campus building.

Community College of Philadelphia’s main campus in Spring Garden was locked down on Tuesday after police say a young man pulled a gun during a dispute at the school. Police arrested a 17-year-old suspect shortly before noon.

The main campus of the Community College of Philadelphia was put on lockdown around 9:30 a.m. as SWAT officers swept the Winnet Student Life Building along 17th Street near Spring Garden Street, Philadelphia Police said.

Community College of Philadelphia

About two hours later, Philadelphia Police Commissioner Charles Ramsey said that police apprehended a 17-year-old suspect in a classroom inside the business school. He didn't, however, have a gun on him. Video from inside the school showed police leading a zip-tied young man from the building. Officers, one carrying a backpack, later led the hoodie-wearing suspect into Central Detectives.

Witnesses told officers that two males who knew each other got into an argument on the street outside the Winnet Building. At some point the suspect pulled a gun on the other man, who is a student, said Ramsey.

Philadelphia Police searched for a male suspect believed to be involved in an heated argument that put the Community College of Philadelphia on lockdown Tuesday morning.

“He was seen going into that building,” said Ramsey.

Officers searched the building and found no gunman, said Ramsey. They expanded the search to include other classroom buildings and a parking garage.

The incident happened a day after the ATF and FBI told Philadelphia area colleges and universities to be on alert after a nondescript online threat of violence. That threat came to light following a shooting at a Oregon community college where a gunman killed nine people and injured nine others.

Ramsey said he didn't believe the man's motive had anything to do with the threat. There were no reports of shots fired or of any injuries.

It's not immediately clear if the suspect discarded a weapon or never had one. Police continued to search the campus Tuesday afternoon.

@CCPedu lockdown is NOT an active shooter situation. @PhillyPolice are clearing the area & looking for suspect regarding a personal dispute — Philadelphia Police (@PhillyPolice) October 6, 2015

Initially, the college only announced that the Winnet Building was put on lockdown. By 11 a.m., the lockdown spread to the entire main campus as officials asked students to shelter in place.

Police Activity on Campus. Main campus is locked down at this point. Shelter in place in progress. — CC of Philadelphia (@CCPedu) October 6, 2015

As SkyForce10 hovered overhead multiple law enforcement vehicles could be seen blocking roads outside the college. You could also see students with backpacks leaving buildings on campus ahead of police locking down the rest of campus.

After noon, students and staff were released at 18th and Spring Garden as police said the campus would slowly reopen. The lockdown was officially lifted around 12:30 p.m.

Exit campus in a calm, orderly fashion. Normal class schedules and business operations resume Wednesday. Updates at http://t.co/Dy5dMutjHv. — CC of Philadelphia (@CCPedu) October 6, 2015

Police tweeted out directions on how students could pick up their belongings.

All parents / loved ones of @CCPedu students canpoo pick up their students at 15 and spring garden — Eric Gripp (@PPDEricGripp) October 6, 2015

Julia R. Masterman School and the Colonnade Condos, both directly across the street of the campus, were locked down as well. Nearby, St. Joseph's Prep was put on lock in — meaning no one could enter the building.

Students told NBC10 that while they were told to remain in nearby campus buildings, they were able to move around on the floor.

More than 34,000 students attend CCP. The college canceled main campus classes for the rest of the day and night.

This isn't the first gun scare at CCP. Back in May 2014 a student brandished a gun in the West Building of the college's main campus because he was allegedly upset over another student ratting on him. The gunman in that case Ryan Fitch is serving four years of probation on weapons charges.