Harvard professors and officials were set on edge yesterday by news that the elusive Unabomber, a serial bomber who has denounced technology and progress, had sent two letters to area Nobel Prize winners.

The bomber reportedly sent letters to two geneticists who were awarded the Nobel Prize in 1993 for their separate research projects on the structure of DNA: Phillip A. Sharp, a member of the Faculty of the Harvard-MIT Division of Health Sciences and Technology; and Richard J. Roberts, research director of the New England Biolabs.

The Unabomber, who is believed responsible for killing three people and injuring 23 since 1978, has denounced technological civilization and those who make it possible. In a recent letter to the New York Times, he offered to stop his campaign if major media outlets agreed to print a lengthy manifesto.

Joe Wrinn, acting director of the Harvard News Office, yesterday referred all inquires to MIT.

Officials at MIT declined to comment on the reports that Sharp had received a letter form the bomber.

"There is no [press] release, and I don't know of any official acknowledgement that there is such a letter," said a spokesperson for the Institute.

A person answering the phone at Sharp's lab yesterday said he was out of town.

University police yesterday advised faculty to be cautious when opening packages. Harvard Police Chief Paul E. Johnson said he was referring members of the university community to a list of precautions sent out two weeks ago following the bombing in Oklahoma City.

"You never know when this guy's going to strike," Johnson said.

The Chief said that Harvard's police department had received sev- eral calls from people concerned about reportsthat the Unabomber--so called because his previoustargets have included universities andairlines--was targeting Harvard.

"Everyone gets wary--which is a good thing,"Johnson said. "It's a shame that something likethis has to happen to get people's attention."

The FBI confirmed that Roberts had received aletter, while the Boston Herald yesterday reportedSharp's receipt of such a letter.

The bomber reportedly mailed four such lettersfrom Oakland, California on April 20. That sameday he sent a package bomb that exploded on April24 in Sacramento, killing a timber industrylobbyist.

Professors said yesterday the letters sent totheir colleagues reminded them of thesenselessness of the bombings.

Baird Professor of Science Dudley R.Herschbach, a 1986 Nobel laureate in Chemistry,said yesterday he was alarmed by the messages tothe two geneticists, both of whom he knowspersonally.

"It's such a sad thing," he said. "How can youguess what's in the mind of someone like this.[Roberts and Sharp] are people that have madediscoveries that clearly benefit humanity."