On Tuesday police and other authorities dealt with their 11th bomb threat in three weeks at the University of Pittsburgh.

Early morning, the university received a bomb threat that targeted specific building on the campus, including the Litchfield Towers. By mid-morning, another threat was made targeting Chevron Science Center. Late afternoon, two other threats came in, claiming potential attacks in the Cathedral of Learning. The university is now offering a $50,000 reward for information leading to the capture of the person responsible for making the threats, reported Reuters.

The inability to bring this succession of threats to a quick end obviously is a source of frustration for everyone whose life has been disrupted by them, said university Chancellor Mark A. Nordenberg in a statement. But I can assure you that law enforcement professionals are doing everything they can to pursue all possible leads.

On Tuesday, approximately 2 a.m., text messages sent to the Pittsburgh Post-Gazette reporters, prompted university officials to evacuate the campus dormitories. About four hours later, students were allowed to return to their living quarters.

The threats began on February 13, 2012, when someone called in about a potential attack at the Chevron Science Center, the location of the chemistry department, reported Reuters. The most recent threat targeted the science too.

On Monday, two threats were reported in an email and on a university bathroom wall. David Lawrence Hall, a building which contains classrooms, lecture halls and a large auditorium were all evacuated, reported Reuters.

No explosives have been discovered at any location.

I ask all members of the University community to be especially attentive to any unusual activity and to share any relevant information with the University of Pittsburgh Police, said Nordenberg.

University of Pittsburgh police have asked the FBI and handwriting experts to help solve the case, reported the Post-Gazette.

Nordenberg said the threats on Pitt were heartless and evoked the March 8 shootings at Western Psychiatric Institute and Clinic, when John Shick shot six people, killing one, before being shot and killed by police.

Particularly given last month's shootings at the Western Psychiatric Institute and Clinic and recent reminders of violence on other campuses, those responsible for these threats not only lack basic respect for the thousands of people whose lives have been disrupted by them but must possess a heartless streak., said Nordenberg. When those responsible are apprehended, we will work to ensure that they are prosecuted to the full extent of the law. Until then, driven by a different set of values, we will maintain safety as our priority and do our best to cope with whatever further disruptions may come our way.

Anyone with information can contact university police at 412-624-2121 or police@pitt.edu.