PITTSBURGH — Federal agents have seized an email server from a New York City hosting service as part of their investigation into a rash of bomb threats targeting the University of Pittsburgh.

May First/People Link officials said Thursday FBI agents served the company with a search warrant a day earlier and removed a server operated by a European service provider that allows users to send anonymous emails.

Dozens of threats have been reported targeting the university over the last two months. Some have been received by media outlets while others were found scrawled in bathrooms. The most recent threats were received Thursday.

May First/People Link says the anonymous email system is intended to make tracing correspondence impossible. The company says such systems serve an important purpose for activists and whistleblowers.