UPDATE: (1:54 a.m.): At 11:35 p.m. Wednesday night, approximately half an hour after initial sirens went off, UNC released a statement that included details of the reported armed robberies.
According to the Alert Carolina website, a male was walking near Aycock Hall just before 11 p.m. when he was approached by two males who reportedly brandished a hand gun. The suspects demanded the victim's wallet.
A few minutes later the suspects, now in a white four-door sedan, reportedly approached a female victim, brandished a handgun and demanded property.
UPDATE (1:18 a.m.): Robbi Pickeral, a spokeswoman for the University, said she could not answer specific questions about the Alert Carolina system's timeline at this time.
She said the statement issued by Alert Carolina calling the response a communication breakdown was coordinated by University communications and public affairs and the UNC Department of Public Safety.
UPDATE (1:00 a.m.): The University released a statement early Thursday morning calling the Alert Carolina system's response to the reported armed robberies on campus a breakdown in communication.
"Per our Alert Carolina protocols, sirens were immediately activated," the statement said.
"However, follow-up notifications were not issued for approximately 45 minutes; the system failed."
UPDATE (12:03 a.m.): Alert Carolina has issued an "all clear."
11:40 p.m.: Alarms went off around 11 p.m. Wednesday night on UNC's campus accompanied by a voice message about an armed person on campus.
Lt. Steve Lehew, the watch commander for Chapel Hill police, said there were two armed robberies on campus. He directed all questions to University police.
"No one's running around with a gun or anything like that," he said.
Alert Carolina issued a warning of an armed and dangerous person on or near campus. An all clear siren went off, but library staff said it was not an all clear signal and it was not safe for students to leave the library.
Check back with The Daily Tar Heel for updates.
This story has been updated to include additional information.
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