This was a developing story. Updates were posted here until 3pm today. The complete story can now be found here.

Reports of a gunman on campus were “confirmed” near Old Campus, where freshmen dorms are housed, by a text update from the University around 11 a.m. Announcements have been broadcast in dorm rooms and sightings of police and the SWAT team have been reported outside Old Campus. New Haven Police Department Lieutenant Jeff Hoffman confirms no shootings, no injuries.

Rob O’Gara ’16, said that police are concentrated on Elm Street between Saybrook, Berkeley and Old Campus. O’Gara said that, for the past 20 minutes, police have been yelling at each other to “get cover” and at someone else — likely the gunman — to pull back. The standoff has continued since, and officers seen near Saybrook are reported to be carrying rifles.

Many students have left campus for Thanksgiving break, but those interviewed from campus said that they have not noticed anything unusual other than the alert messages.

Maria Bouffard, director of emergency management, confirmed that NHPD and YPD officers have been brought to the scene. Bouffard said that updates will continue to be posted on the University’s official emergency services website as they are received.

At 10:20 a.m., the Yale emergency alert system sent out phone calls and text messages to students notifying them of reports of a man with a gun on campus. The messages indicated that an anonymous tip to the NHPD had been made from a phone booth on Columbus Avenue. The messages told students to remain in place. The University’s PA system, which is used to announce other emergency situations like fires, has not been used.

Cops were not seen around Pierson or Calhoun colleges as of 10:37 a.m. A 10:50 a.m. text update to students stated the shelter was still in place. At 11:55 a.m. a text update confirmed that the shelter in place and lock-down remain in effect. 12:16 p.m. Traffic was being diverted by New Haven police, and ambulances were are on the scene as a precaution. It is not clear whether anyone is inside. According to NBC Connecticut, the following streets are closed:

High Street between Elm and Chapel streets

Chapel Street between High and College streets College Street between Chapel and Elm streets Elm Street between College and High streets

12:31 p.m. According toJeff Hoffman one person has been detained, and is being interviewed the by the YPD and the NHPD. He was arrested on Elm Street, near College Street, but did not have a gun on him. Hoffman said there still has not been a sighting of anyone in possession of a gun. Hoffman added he could not confirm rumors of a gunman inside of Battell Chapel. The search appears to be continuing for the suspect. Reports have been that the suspect is a white male, some saying with a backpack and rifle.

The New Haven Independent reported that a Yale student called the police to report that his roommate “wanted to shoot up the school” on Monday. Hoffman said that a call from the Hill neighborhood was the reason for the initial lockdown. However, the caller did not remain on the scene and did not talk the police, calling his credibility into doubt. 1:25 p.m. New Haven Police Department spokesman David Hartman said the call lasted only a few seconds, and was from a payphone at 9:30 a.m. this morning. Hartman described the call as “a statement,” that the caller’s roommate was headed to campus with a gun. The caller was male and did not identify himself as a Yale student. Hartman said that no suspect has been detained, and that reports from witnesses interviewed have been contradictory. According to NBC, SWAT teams are conducting searches to clear buildings on Old Campus. Gateway Community College is on a precautionary lockdown, as are several New Haven Public Schools.

1:45 p.m. Yale Alert sends a text message to the Yale Community that police are conducting room to room searches beginning with the residential colleges, and that the shelter in place continues. A following call said that the police would identify themselves by slipping a Yale ID under the door, and requested that students cooperate. It added that in some areas Yale Police may simply use keys.

1:55 p.m. In an update from Hartman, he said, “Things are pretty status quo as far as our investigation is concerned.” Hartman confirmed that the NHPD and YPD are being supplemented by the FBI and Connecticut state police. He added that earlier reports of sightings of someone with a long gun may in fact have referred to law enforcement officers responding to the situation. Hartman confirmed that no one is in custody at the moment and said that an all clear will likely not be given for at least several hours.

2:25 p.m. NBC reports that border patrol and Department of Homeland Security are also on the scene. There have still been no reports of a gun fired or injuries on campus.

Tasnim Elboute and Isaac Stanley-Becker contributed reporting.