Harvard and local police received threats by phone yesterday morning that bombs had been placed in the Kennedy School of Government and at the Harvard Medical School, just one day after the Charles Hotel complex received a similar threat.

Neither Harvard building was evacuated, though the Kennedy School was searched, and officials at both Harvard schools warned students and staff of the threats.

Harvard police received the first phone call around 9 a.m., when "a female voice stated there was a bomb" at the Kennedy School, according to Harvard Police Chief Paul E. Johnson. A half-hour later, a female caller told Needham police, "A bomb will go off in one hour at the Best Western Hotel of Harvard Medical School," Johnson said. Needham police passed the information to the Harvard police.

Harvard police discussed the matter with heads of the Kennedy School before taking any action, Johnson said.

"The general sense was, after discussion with the police, not to evacuate the building, but to inform people," said Kennedy School spokesperson Steven R. Singer.

Singer said it's not uncommon for the Kennedy School to receive bomb threats. He said this one didn't cause particular alarm because "It was a vague and unspecific call."

"In the absence of any hard evidence we had reason to believe that [the threat] was not serious," Johnson said. Johnson made the same conclusion regarding the Medical School bomb threat.

At the Kennedy School, there was no large-scale search, Singer said, but "a few people went through the whole school."

"People were asked to check their own areas because they are most familiar with what boxes and packages belong there," he said.

In addition, students and staff were warned of the call with notices plastered in doorways urging anyone to leave should they "feel their safety is compromised."

Officials also left voice mail messages about the bomb threat, Singer said.

Similar measures were taken at the Medical School, Johnson said. Police have not been able to identify either caller or establish any relation between the two, or a third bomb threat received Thursday by the Charles Hotel.

Gary Gainnino, property manager of the Charles Hotel, said that a caller to the residences at the Charles Hotel on 975 Memorial Drive had claimed that some United Parcel Service packages to be delivered that day "contained some stuff that could hurt some people."

"Cambridge police, assisted by the Boston police, searched the packages, and nothing came of it," he said.

It is unclear whether any of the phone threats had any connection to the World Trade Center explosion that drew national attention last week