DALLAS (CBSDFW.COM) – Students and faculty at El Centro College in downtown Dallas hunkered down inside classrooms while the school was on an intruder lockdown Tuesday.

The Dallas County Community College District Emergency Alert System sent a message for them to “Proceed with others to the nearest room and barricade and/or lock yourselves in the room. Wait in place for further instructions from police. If you are not on campus, STAY AWAY for your own safety.”

DCCCD Police officers assisted DART officers who were pursuing three men allegedly involved in a robbery.

Two of the suspects were apprehended by DART officers outside the college.

But DCCCD did a sweep inside the school in an “abundance of caution” to ensure that the third suspect wasn’t in the building.

Once the sweep was completed and all floors were cleared, the lockdown was lifted.