Several students who work as assistants in the building said they had been made aware of bomb threats, though neither HUPD or William James Hall officials would confirm them.

"If [one] was received [by William James Hall], then it wasn't called in to us," McNamara said.

In an unrelated incident yesterday, an hour examination for Literature and Arts A-18: "Fairy Tales" in the Fogg Art Museum's Norton Room was delayed when a bomb threat was called in just before noon.

Police searched the bags of students as they entered. The exam began

without incident, 30 minutes later.

--Garrett M. Graff and Matthew F. Quirk contributed to the reporting of this article.