IOWA CITY, Iowa (AP) _ Faculty and students at the University of Iowa mourned on Monday as a funeral and memorial services replaced classes two days after a vengeful former student went on a shooting spree.

Gang Lu, who received a Ph.D. in physics, killed three professors, an administrator and a student whose dissertation was honored over his last spring. A sixth victim was seriously wounded.

After the rampage, which included a return to the scene of the first three shootings to finish off a victim, Lu killed himself.

''We all truly feel the shock and dismay, as with the families, over the loss of our loved ones,'' said Henry McGill, 20, an engineering student from Marion, S.C., who presided over a memorial ceremony on campus.

''It is midnight at the university right now,'' he said.

Flags were at half-staff on campus and classes were canceled for the day. More than 500 people grieved at a funeral for a slain administrator. Several hundred attended other memorial gatherings.

''The injuries we have suffered are devastating. We cannot make sense of this; we are out of our depth,'' said Hunter Rawlings, president of the 28,000-student university.

''Suddenly, without warning, in less than an hour last Friday afternoon, the university was senselessly diminished,'' he said.

Elsewhere on campus, hundreds of students and faculty held brief, silent vigils and placed wreaths near the shooting sites in memory of the victims. A university-wide service was scheduled Thursday at Carver-Hawkeye Arena.

Lu, 28, was assisting in university research while looking for permanent work, despite his anger over his doctoral dissertation not receiving an academic honor, authorities said.

One of Lu's victims was T. Anne Cleary, an associate vice president for academic affairs. Lu had filed a complaint with Cleary over the honors nomination process.

Two red roses were placed in the form of a cross on her casket in a funeral at St. Patrick's Church. The Rev. Paul Deyo remembered her positive spirit.

''Anne would be the first to scold us should we allow animosity or anger to cloud this day,'' he said.

Cleary's brothers - Frank, Mike and Paul - planned to send a letter to Lu's parents in China ''to share with them their prayers and their hope that grief may soon give way to peace and trust,'' Deyo.

University officials were trying to locate family or relatives of Lu, who came to the United States from Beijing in 1985, said Ann Rhodes, vice president of university relations.

His visa, as well as those of about 300 other Chinese students on campus, was extended until 1994 by President Bush after the Tiananmen Square massacre in 1989, Rhodes said.

Lu opened fire with a .38-caliber pistol at a weekly physics and astronomy department meeting, shooting two professors and Linhua Shan, the student whose dissertation was selected over Lu's.

He killed a third professor in his office and then returned to the first shooting site, where he finished off a victim who was still alive.

He then moved to another building, where he killed Cleary and shot Miya Rodolfo-Sioson, an assistant who remained in serious condition at University Hospitals. Killed in addition to Cleary and Shan were department chairman Dwight Nicholson, professor Christoph Goertz and associate professor Robert Alan Smith.

Les Sims, dean of the university's graduate school, said Lu's dissertation needed changes just before the April 29 deadline. The changes were made and his paper was submitted in time, he said.

''His thesis, indeed, had been considered very highly competitive for the nomination and it was adequately considered,'' Sims said.