In an anonymous act of racism, three Penn State students and one member of the Penn State Board of Trustees received threatening letters during the past several days, university officials said yesterday.

"We don't know anything about the people who sent this message except they're cowards," said Terrell Jones, vice-provost for educational equity.

At least one of the students had received a similar threat before, Jones said.

Penn State Police Services is working with the FBI, the office of the state Attorney General and the U.S. Postal Service to track down who sent the letters.

The letters were short, typed notes sent through the U.S. mail, said Penn State spokesman Bill Mahon.

"It's just hate mail. The worst kind of stuff you'd expect to read," Mahon said.

Students who were targeted said the messages point to a larger problem of racism in the university community, Jones said.

"This is one of these trigger incidents that lets people know we have an issue," he said.

The three students appear to have been singled out because they were all quoted recently in Daily Collegian articles, Jones added.

Neither Jones nor Mahon would elaborate on what the messages said, but both said they contained typical racist rhetoric.

"While they're aimed at an individual, the message here is to tell the whole minority community 'You don't belong,' " Jones said.

Penn State President Graham Spanier expressed his anger toward the letters in a press release.

"We are committed to having an environment of respect and civility within our university, and we are going to do everything in our power to find the person responsible for sending these messages," Spanier said.

Dozens of minority students at Penn State received harassing e-mails from an anonymous character last fall who went by the name "The Patriot."

In addition, police investigated a racist flier that was discovered on the floor of a restroom in Paterno Library in January.

More recently, three black students reported that two white men threw rocks at them from the top of a residence hall building one night last month. Police charged two men who they say were involved in the rock throwing.