Investigators searching for Annie Le, the 24-year-old Yale graduate student missing since Tuesday, have found bloody clothes above a ceiling tile in the building where Le was last seen, a police source told The Courant Saturday.

But no body had been found as of Saturday evening, and investigators were still searching for Le, Yale Vice President and Secretary Linda Lorimer at a press conference.

"The investigation is at a very difficult time," Lorimer said.

Kim Mertz, the FBI special agent in charge of the case, said Saturday that items that might be evidence have been collected from the research building at 10 Amistad St., in the Yale Medical School complex.

"We don't know if they could be associated with Annie Le," she said. "We have not identified anyone as a person of interest."

She added, "We're not in a position today to say whether this is a missing person case or whether criminality is involved."

University spokesman Tom Conroy said, "We don't know where she is, we don't know what happened to her."

Le, whose planned marriage Sunday on Long Island has been canceled, has been the focus of an intensive search since her disappearance. Dozens of Yale, New Haven and state police and FBI agents have been involved in the search, which continues to focus on the Amistad Street building.

Police said they have interviewed numerous people, including some who saw Le inside the building. Le was last seen entering the laboratory building about 10 a.m. Tuesday. But investigators have been unable to find any record of her leaving, despite spending hours poring over tapes from some 75 surveillance cameras that cover the complex.

Lorimer said it was "entirely perplexing that there doesn't seem to be a record of her" leaving the building, according to the Yale Daily News.

Investigators, having already gone through the videos once, were reviewing the surveillance tapes frame by frame to see if they overlooked Le, who could have changed into a laboratory coat or other clothing before leaving the building.

On Saturday, they brought in what appeared to be the building's blueprints. FBI agents also were spotted questioning an unidentified man outside the lab. When they finished talking, the man got into the front seat of an unmarked car and an FBI agent got into the back seat. The car then drove away.

Agent Bill Reiner said the FBI would not answer any questions about the investigation while it is still underway.

Yale is offering a $10,000 reward for information leading to Le's whereabouts. She is described as being of Asian descent, 4 feet 11 inches tall and 90 pounds. Her purse, cellphone, credit cards and money were found in her office in the lab building.

Le, originally from Placerville, Calif., was to get married Sunday at the North Ritz Club in Syosset, N.Y. Workers at the club said the wedding was canceled on Friday.

Police said her fiancé, Jonathan Widawsky, a graduate student at Columbia University in New York City, is not a suspect and is assisting with the investigation.

During the evening, as many as six uniformed Yale and New Haven police officers stood guard outside the building's main entrance and the ramp to its parking garage. They carefully checked IDs of people who tried to get in, and turned away several. One woman arrived with a Yale ID card and told them she'd been called in to work that evening, but they sent her away, saying the basement --where she was assigned to work -- was closed off.

Saturday evening, two young women strode to a tree along Amistad and put up a cardboard sign bearing the message "Annie -- We Hope You Are Okay!! -- Yale Grad Students."

One, who identified herself only as Kristina, said she and other Yale grad students are frightened and want more information from school administrators.

"The grad students are terrified," she said. "A lot of us are female and small, and we don't feel safe. We haven't heard anything from the dean of medicine or from anybody except the Yale police."

The woman said she doesn't know Le personally, but heard her give a presentation on pharmacology last year.

"I remember thinking, 'She's very together, she's very impressive,'." the woman said. "I hope she's OK."

Meanwhile at Le's apartment building across town, hopes for Le's safe return waned.

"I feel bad what happened to her," said Anna Beth Funk, who lives across the street from Le's apartment. "It broke my heart hearing she was about to get married because I love being married and it must be so hard for her fiance."

Wesleyan University professor Charles Lemert, who also lives across the street, said Le always took time to talk to his 11-year-old daughter.

"I wish more than anything this could be solved and turn into some kind of misunderstanding, but it seems bleak," he said.


-- Associated Press reports are included in this story.