Delaware County Community College opened peacefully today, but with a heavy security presence on its five campuses.

That included the Exton and Downingtown campuses, which were the focus of e-mail threats sent last week that prompted officials to close the college last Thursday.

At the Downingtown campus for the 8 a.m. classes, all but the main entrance was locked, and at that door students and faculty were greeted by three police officers who were checking for college ID cards.

Inside a classroom at the Exton campus, Alexandra Pavlova, 18, from Downingtown, said, "I'm here to get my A's, I don't want to put that at stake. School is not supposed to be a place where you feel unsafe."

Pavlova's earth sciences teacher, Claude Cazanave, said, "I sympathize a lot with the students if they feel uneasy," and would not penalize students for not attending class today.

Police cars were parked near the two classroom buildings, and a bomb-sniffing dog was present.

Keith Beaumont, 25, from West Chester, said, "I was never really that nervous. With finals coming up, somebody did something stupid to get out of that."

A voice-mail message had been sent to students the day before, notifying them that classes would resume, and warning them not to carry backpacks or book bags. Faculty had been notified by e-mail or in a meeting yesterday at the main campus.

Despite the early hour and the security, there didn't seem to be any more absences than usual, though some students had e-mailed teachers that their parents had advised them not to attend class today. One student decided to come in anyway because she was curious about what campus would be like.

Calling the threat "domestic terrorism" that disrupted thousands of lives, Chester County District Attorney Joseph W. Carroll yesterday said he believed that the heavy police presence and security precautions would deter any violence.

Carroll said evidence suggested that the writer of the e-mails sent Thursday, who threatened "to kill everyone at this damn school," intended to disrupt campus operations rather than end lives.

But officials were obliged to take the threats seriously, he said.

"The recent events at Virginia Tech and our collective experience with other school shootings make it impossible to ignore the possibility that a deranged killer would make good on his word," said Carroll, referring to the April 16 slaying of 32 students and staff, and the suicide of the gunman.