An e-mail threat to the two Delaware County Community College campuses in Chester County that was deemed to be credible has prompted school officials to shut down the remaining three locations at least until Monday.

Yesterday, about 12:30 p. m., about a dozen e-mails were received at the Exton and Downingtown campuses, threatening "violence against numerous persons," said Sgt. Martin Malloy, of the West Whiteland Police.

Malloy said a search warrant is in the process of being served in an attempt to find the person who sent the e-mail. He said they believe, based on the contents of the message, that the sender may be a student. Malloy would not disclose the contents of the message.

College officials contacted police as more of the e-mails, which were sent to college departments, were discovered by employees.

The college, which serves about 10,000 day students, also has campus locations in Marple, Sharon Hill and Broomall in Delaware County.

"We started to take action about 3 p.m.," said Fran Cubberley, an associate vice president at the school. Cubberley said they sent e-mail to all employees, posted a notice on the campus Web site, and used a phone broadcast system to alert students that classes were canceled.

Cubberley said that school officials were playing it "day by day" and would not resume classes until they thought it is safe to do so.

"I think that certainly we made the decision to close all college locations probably in the shadow of what happened at Virginia Tech," said Cubberley, who added that school officials normally are conservative with security matters.

Contact staff writer Mari A. Schaefer at 610-892-9149 or mschaefer@phillynews.com.

Staff writer Kathleen Brady Shea contributed to this article.