Classes at Delaware County Community College are canceled tomorrow - for a fourth day - while police try to find the person who issued threatening e-mails that hint of a Virginia Tech-style massacre.

"The e-mails were written by a rather disturbed individual who was threatening violence on a large scale," West Whiteland Police Sgt. Martin Malloy, who is investigating the threat, said today. "He or she described a deed that would remind you of what happened at Virginia Tech." He would not elaborate further.

The college suspended classes Thursday afternoon at all five of its campuses, in Chester and Delaware Counties, after about a dozen threatening e-mails were received. The college has an enrollment of about 10,000 day students.

Malloy said that college officials planned to close until they are assured by authorities that the campuses are safe. "We are actively working the case," said Malloy. "Had this happened a month ago we would not be as concerned. But now, after Virginia Tech, we are taking this very seriously."

On April 16, Virginia Tech student Seung-Hui Cho killed 32 and wounded at least 15 during a campus rampage before killing himself.

In a letter to students, posted today on the college Web site, college president Jerome S. Parker wrote: "A decision regarding reopening will not be made until we are assured by the authorities that it is safe to do so. The safety of our College community is of the utmost importance. We apologize for any inconvenience and thank our students, faculty and staff, along with our community, for your continuing patience and cooperation."

Fran Cubberley, associate vice president at the college, said that the police, the FBI and other investigating agencies all recommended the college remain closed. "They still don't know who the perpetrator is," she said.

Malloy said that police plan to obtain a second search warrant tomorrow that may help them determine the identity of the person who has made the threats.

Meanwhile, a nearly two-week-old threat predicting a bombing at Penn State Abington today caused police to close the Montgomery County campus today and sweep it with police and bomb-sniffing dogs. The campus was declared clear and the threat was found "not credible," school spokesman Chuck Marsh said, and the campus was to reopen tomorrow.

Abington Police and campus police have been investigating the bomb threat scrawled on a bathroom wall and discovered April 18. Parents and students were notified by e-mail the next day, Marsh said.

Marsh would not describe the specific wording of the threat; he said it was "vague" in referring to a bombing, but very specific with a date - April 30. Abington police will provide extra security at the campus tomorrow.